diff --git a/packages/plugin-ext/src/common/plugin-api-rpc.ts b/packages/plugin-ext/src/common/plugin-api-rpc.ts
index 552ab5e1db69b..300c23d789240 100644
--- a/packages/plugin-ext/src/common/plugin-api-rpc.ts
+++ b/packages/plugin-ext/src/common/plugin-api-rpc.ts
@@ -248,7 +248,7 @@ export interface CommandRegistryExt {
 export interface TerminalServiceExt {
     $terminalCreated(id: string, name: string): void;
     $terminalNameChanged(id: string, name: string): void;
-    $terminalOpened(id: string, processId: number, cols: number, rows: number): void;
+    $terminalOpened(id: string, processId: number, terminalId: number, cols: number, rows: number): void;
     $terminalClosed(id: string): void;
     $terminalOnInput(id: string, data: string): void;
     $terminalSizeChanged(id: string, cols: number, rows: number): void;
@@ -283,7 +283,7 @@ export interface TerminalServiceMain {
 
     /**
      * Send text to the terminal by id.
-     * @param id - terminal id.
+     * @param id - terminal widget id.
      * @param text - text content.
      * @param addNewLine - in case true - add new line after the text, otherwise - don't apply new line.
      */
@@ -291,14 +291,14 @@ export interface TerminalServiceMain {
 
     /**
      * Write data to the terminal by id.
-     * @param id - terminal id.
+     * @param id - terminal widget id.
      * @param data - data.
      */
     $write(id: string, data: string): void;
 
     /**
      * Resize the terminal by id.
-     * @param id - terminal id.
+     * @param id - terminal widget id.
      * @param cols - columns.
      * @param rows - rows.
      */
@@ -306,23 +306,66 @@ export interface TerminalServiceMain {
 
     /**
      * Show terminal on the UI panel.
-     * @param id - terminal id.
+     * @param id - terminal widget id.
      * @param preserveFocus - set terminal focus in case true value, and don't set focus otherwise.
      */
     $show(id: string, preserveFocus?: boolean): void;
 
     /**
      * Hide UI panel where is located terminal widget.
-     * @param id - terminal id.
+     * @param id - terminal widget id.
      */
     $hide(id: string): void;
 
     /**
      * Destroy terminal.
-     * @param id - terminal id.
+     * @param id - terminal widget id.
      */
     $dispose(id: string): void;
 
+    /**
+     * Send text to the terminal by id.
+     * @param id - terminal id.
+     * @param text - text content.
+     * @param addNewLine - in case true - add new line after the text, otherwise - don't apply new line.
+     */
+    $sendTextByTerminalId(id: number, text: string, addNewLine?: boolean): void;
+
+    /**
+     * Write data to the terminal by id.
+     * @param id - terminal id.
+     * @param data - data.
+     */
+    $writeByTerminalId(id: number, data: string): void;
+
+    /**
+     * Resize the terminal by id.
+     * @param id - terminal id.
+     * @param cols - columns.
+     * @param rows - rows.
+     */
+    $resizeByTerminalId(id: number, cols: number, rows: number): void;
+
+    /**
+     * Show terminal on the UI panel.
+     * @param id - terminal id.
+     * @param preserveFocus - set terminal focus in case true value, and don't set focus otherwise.
+     */
+    $showByTerminalId(id: number, preserveFocus?: boolean): void;
+
+    /**
+     * Hide UI panel where is located terminal widget.
+     * @param id - terminal id.
+     */
+    $hideByTerminalId(id: number): void;
+
+    /**
+     * Destroy terminal.
+     * @param id - terminal id.
+     * @param waitOnExit - Whether to wait for a key press before closing the terminal.
+     */
+    $disposeByTerminalId(id: number, waitOnExit?: boolean | string): void;
+
     $setEnvironmentVariableCollection(extensionIdentifier: string, persistent: boolean, collection: SerializableEnvironmentVariableCollection | undefined): void;
 }
 
@@ -1718,7 +1761,7 @@ export const MAIN_RPC_CONTEXT = {
 export interface TasksExt {
     $provideTasks(handle: number, token?: CancellationToken): Promise<TaskDto[] | undefined>;
     $resolveTask(handle: number, task: TaskDto, token?: CancellationToken): Promise<TaskDto | undefined>;
-    $onDidStartTask(execution: TaskExecutionDto): void;
+    $onDidStartTask(execution: TaskExecutionDto, terminalId: number, resolvedDefinition: theia.TaskDefinition): void;
     $onDidEndTask(id: number): void;
     $onDidStartTaskProcess(processId: number | undefined, execution: TaskExecutionDto): void;
     $onDidEndTaskProcess(exitCode: number | undefined, taskId: number): void;
@@ -1731,6 +1774,7 @@ export interface TasksMain {
     $taskExecutions(): Promise<TaskExecutionDto[]>;
     $unregister(handle: number): void;
     $terminateTask(id: number): void;
+    $customExecutionComplete(id: number, exitCode: number | undefined): void;
 }
 
 export interface AuthenticationExt {
diff --git a/packages/plugin-ext/src/main/browser/tasks-main.ts b/packages/plugin-ext/src/main/browser/tasks-main.ts
index 7cb79fa8f839e..2ef9ce7f3ea48 100644
--- a/packages/plugin-ext/src/main/browser/tasks-main.ts
+++ b/packages/plugin-ext/src/main/browser/tasks-main.ts
@@ -30,6 +30,7 @@ import { TaskInfo, TaskExitedEvent, TaskConfiguration, TaskCustomization, TaskOu
 import { TaskWatcher } from '@theia/task/lib/common/task-watcher';
 import { TaskService } from '@theia/task/lib/browser/task-service';
 import { TaskDefinitionRegistry } from '@theia/task/lib/browser';
+import * as theia from '@theia/plugin';
 
 const revealKindMap = new Map<number | RevealKind, RevealKind | number>(
     [
@@ -73,10 +74,19 @@ export class TasksMainImpl implements TasksMain, Disposable {
         this.taskDefinitionRegistry = container.get(TaskDefinitionRegistry);
 
         this.toDispose.push(this.taskWatcher.onTaskCreated((event: TaskInfo) => {
+            const taskDefinition = {
+                type: event.config.type
+            } as theia.TaskDefinition;
+            const { type, ...properties } = event.config;
+            for (const key in properties) {
+                if (properties.hasOwnProperty(key)) {
+                    taskDefinition[key] = properties[key];
+                }
+            }
             this.proxy.$onDidStartTask({
                 id: event.taskId,
                 task: this.fromTaskConfiguration(event.config)
-            });
+            }, event.terminalId!!, taskDefinition);
         }));
 
         this.toDispose.push(this.taskWatcher.onTaskExit((event: TaskExitedEvent) => {
@@ -177,6 +187,10 @@ export class TasksMainImpl implements TasksMain, Disposable {
         this.taskService.kill(id);
     }
 
+    async $customExecutionComplete(id: number, exitCode: number | undefined): Promise<void> {
+        this.taskService.customExecutionComplete(id, exitCode);
+    }
+
     protected createTaskProvider(handle: number): TaskProvider {
         return {
             provideTasks: () =>
diff --git a/packages/plugin-ext/src/main/browser/terminal-main.ts b/packages/plugin-ext/src/main/browser/terminal-main.ts
index 9ab198ce42281..083fe0e6800f1 100644
--- a/packages/plugin-ext/src/main/browser/terminal-main.ts
+++ b/packages/plugin-ext/src/main/browser/terminal-main.ts
@@ -85,7 +85,7 @@ export class TerminalServiceMainImpl implements TerminalServiceMain, Disposable
         this.toDispose.push(Disposable.create(() => terminal.title.changed.disconnect(updateTitle)));
 
         const updateProcessId = () => terminal.processId.then(
-            processId => this.extProxy.$terminalOpened(terminal.id, processId, terminal.dimensions.cols, terminal.dimensions.rows),
+            processId => this.extProxy.$terminalOpened(terminal.id, processId, terminal.terminalId, terminal.dimensions.cols, terminal.dimensions.rows),
             () => {/* no-op */ }
         );
         updateProcessId();
@@ -174,4 +174,58 @@ export class TerminalServiceMainImpl implements TerminalServiceMain, Disposable
             terminal.dispose();
         }
     }
+
+    $sendTextByTerminalId(id: number, text: string, addNewLine?: boolean): void {
+        const terminal = this.terminals.getByTerminalId(id);
+        if (terminal) {
+            text = text.replace(/\r?\n/g, '\r');
+            if (addNewLine && text.charAt(text.length - 1) !== '\r') {
+                text += '\r';
+            }
+            terminal.sendText(text);
+        }
+    }
+    $writeByTerminalId(id: number, data: string): void {
+        const terminal = this.terminals.getByTerminalId(id);
+        if (!terminal) {
+            return;
+        }
+        terminal.write(data);
+    }
+    $resizeByTerminalId(id: number, cols: number, rows: number): void {
+        const terminal = this.terminals.getByTerminalId(id);
+        if (!terminal) {
+            return;
+        }
+        terminal.resize(cols, rows);
+    }
+    $showByTerminalId(id: number, preserveFocus?: boolean): void {
+        const terminal = this.terminals.getByTerminalId(id);
+        if (terminal) {
+            const options: WidgetOpenerOptions = {};
+            if (preserveFocus) {
+                options.mode = 'reveal';
+            }
+            this.terminals.open(terminal, options);
+        }
+    }
+    $hideByTerminalId(id: number): void {
+        const terminal = this.terminals.getByTerminalId(id);
+        if (terminal && terminal.isVisible) {
+            const area = this.shell.getAreaFor(terminal);
+            if (area) {
+                this.shell.collapsePanel(area);
+            }
+        }
+    }
+    $disposeByTerminalId(id: number, waitOnExit?: boolean | string): void {
+        const terminal = this.terminals.getByTerminalId(id);
+        if (terminal) {
+            if (waitOnExit) {
+                terminal.waitOnExit(waitOnExit);
+                return;
+            }
+            terminal.dispose();
+        }
+    }
 }
diff --git a/packages/plugin-ext/src/plugin/plugin-context.ts b/packages/plugin-ext/src/plugin/plugin-context.ts
index 76b343fef1379..08969dd8b77b8 100644
--- a/packages/plugin-ext/src/plugin/plugin-context.ts
+++ b/packages/plugin-ext/src/plugin/plugin-context.ts
@@ -95,6 +95,7 @@ import {
     ShellQuoting,
     ShellExecution,
     ProcessExecution,
+    CustomExecution,
     TaskScope,
     TaskPanelKind,
     TaskRevealKind,
@@ -194,7 +195,7 @@ export function createAPIFactory(
     const outputChannelRegistryExt = rpc.set(MAIN_RPC_CONTEXT.OUTPUT_CHANNEL_REGISTRY_EXT, new OutputChannelRegistryExtImpl(rpc));
     const languagesExt = rpc.set(MAIN_RPC_CONTEXT.LANGUAGES_EXT, new LanguagesExtImpl(rpc, documents, commandRegistry));
     const treeViewsExt = rpc.set(MAIN_RPC_CONTEXT.TREE_VIEWS_EXT, new TreeViewsExtImpl(rpc, commandRegistry));
-    const tasksExt = rpc.set(MAIN_RPC_CONTEXT.TASKS_EXT, new TasksExtImpl(rpc));
+    const tasksExt = rpc.set(MAIN_RPC_CONTEXT.TASKS_EXT, new TasksExtImpl(rpc, terminalExt));
     const connectionExt = rpc.set(MAIN_RPC_CONTEXT.CONNECTION_EXT, new ConnectionExtImpl(rpc));
     const fileSystemExt = rpc.set(MAIN_RPC_CONTEXT.FILE_SYSTEM_EXT, new FileSystemExtImpl(rpc, languagesExt));
     const extHostFileSystemEvent = rpc.set(MAIN_RPC_CONTEXT.ExtHostFileSystemEventService, new ExtHostFileSystemEventService(rpc, editorsAndDocumentsExt));
@@ -910,6 +911,7 @@ export function createAPIFactory(
             ShellQuoting,
             ShellExecution,
             ProcessExecution,
+            CustomExecution,
             TaskScope,
             TaskRevealKind,
             TaskPanelKind,
diff --git a/packages/plugin-ext/src/plugin/tasks/tasks.ts b/packages/plugin-ext/src/plugin/tasks/tasks.ts
index 1e5ea1dbd3035..2494915b2c911 100644
--- a/packages/plugin-ext/src/plugin/tasks/tasks.ts
+++ b/packages/plugin-ext/src/plugin/tasks/tasks.ts
@@ -23,10 +23,11 @@ import {
 } from '../../common/plugin-api-rpc';
 import * as theia from '@theia/plugin';
 import * as converter from '../type-converters';
-import { Disposable } from '../types-impl';
+import { CustomExecution, Disposable } from '../types-impl';
 import { RPCProtocol, ConnectionClosedError } from '../../common/rpc-protocol';
 import { TaskProviderAdapter } from './task-provider';
 import { Emitter, Event } from '@theia/core/lib/common/event';
+import { TerminalServiceExtImpl } from '../terminal-ext';
 
 export class TasksExtImpl implements TasksExt {
     private proxy: TasksMain;
@@ -34,6 +35,8 @@ export class TasksExtImpl implements TasksExt {
     private callId = 0;
     private adaptersMap = new Map<number, TaskProviderAdapter>();
     private executions = new Map<number, theia.TaskExecution>();
+    protected providedCustomExecutions: Map<string, CustomExecution>;
+    protected activeCustomExecutions: Map<number, CustomExecution>;
 
     private readonly onDidExecuteTask: Emitter<theia.TaskStartEvent> = new Emitter<theia.TaskStartEvent>();
     private readonly onDidTerminateTask: Emitter<theia.TaskEndEvent> = new Emitter<theia.TaskEndEvent>();
@@ -42,8 +45,10 @@ export class TasksExtImpl implements TasksExt {
 
     private disposed = false;
 
-    constructor(rpc: RPCProtocol) {
+    constructor(rpc: RPCProtocol, readonly terminalExt: TerminalServiceExtImpl) {
         this.proxy = rpc.getProxy(PLUGIN_RPC_CONTEXT.TASKS_MAIN);
+        this.providedCustomExecutions = new Map<string, CustomExecution>();
+        this.activeCustomExecutions = new Map<number, CustomExecution>();
         this.fetchTaskExecutions();
     }
 
@@ -59,7 +64,24 @@ export class TasksExtImpl implements TasksExt {
         return this.onDidExecuteTask.event;
     }
 
-    $onDidStartTask(execution: TaskExecutionDto): void {
+    async $onDidStartTask(execution: TaskExecutionDto, terminalId: number, resolvedDefinition: theia.TaskDefinition): Promise<void> {
+        const customExecution: CustomExecution | undefined = this.providedCustomExecutions.get(execution.task.id);
+        if (customExecution) {
+            if (this.activeCustomExecutions.get(execution.id) !== undefined) {
+                throw new Error('We should not be trying to start the same custom task executions twice.');
+            }
+
+            // Clone the custom execution to keep the original untouched. This is important for multiple runs of the same task.
+            this.activeCustomExecutions.set(execution.id, customExecution);
+            const pty = await customExecution.callback(resolvedDefinition);
+            this.terminalExt.attachPtyToTerminal(terminalId, pty);
+            if (pty.onDidClose) {
+                pty.onDidClose((e: number | void = undefined) => {
+                    // eslint-disable-next-line no-void
+                    this.proxy.$customExecutionComplete(execution.id, e === void 0 ? undefined : e);
+                });
+            }
+        }
         this.onDidExecuteTask.fire({
             execution: this.getTaskExecution(execution)
         });
@@ -76,6 +98,7 @@ export class TasksExtImpl implements TasksExt {
         }
 
         this.executions.delete(id);
+        this.customExecutionComplete(id);
 
         this.onDidTerminateTask.fire({
             execution: taskExecution
@@ -138,7 +161,16 @@ export class TasksExtImpl implements TasksExt {
     $provideTasks(handle: number, token: theia.CancellationToken): Promise<TaskDto[] | undefined> {
         const adapter = this.adaptersMap.get(handle);
         if (adapter) {
-            return adapter.provideTasks(token);
+            return adapter.provideTasks(token).then(tasks => {
+                if (tasks) {
+                    for (const task of tasks) {
+                        if (task.type === 'customExecution') {
+                            this.providedCustomExecutions.set(task.id, new CustomExecution(task.callback));
+                        }
+                    }
+                }
+                return tasks;
+            });
         } else {
             return Promise.reject(new Error('No adapter found to provide tasks'));
         }
@@ -198,4 +230,11 @@ export class TasksExtImpl implements TasksExt {
         this.executions.set(executionId, result);
         return result;
     }
+
+    private customExecutionComplete(id: number): void {
+        const extensionCallback2: CustomExecution | undefined = this.activeCustomExecutions.get(id);
+        if (extensionCallback2) {
+            this.activeCustomExecutions.delete(id);
+        }
+    }
 }
diff --git a/packages/plugin-ext/src/plugin/terminal-ext.ts b/packages/plugin-ext/src/plugin/terminal-ext.ts
index a2f576deee453..4546588aaa983 100644
--- a/packages/plugin-ext/src/plugin/terminal-ext.ts
+++ b/packages/plugin-ext/src/plugin/terminal-ext.ts
@@ -79,6 +79,10 @@ export class TerminalServiceExtImpl implements TerminalServiceExt {
         return this.obtainTerminal(id, options.name || 'Terminal');
     }
 
+    public attachPtyToTerminal(terminalId: number, pty: theia.Pseudoterminal): void {
+        this._pseudoTerminals.set(terminalId.toString(), new PseudoTerminal(terminalId, this.proxy, pty, true));
+    }
+
     protected obtainTerminal(id: string, name: string): TerminalExtImpl {
         let terminal = this._terminals.get(id);
         if (!terminal) {
@@ -118,7 +122,7 @@ export class TerminalServiceExtImpl implements TerminalServiceExt {
         }
     }
 
-    $terminalOpened(id: string, processId: number, cols: number, rows: number): void {
+    $terminalOpened(id: string, processId: number, terminalId: number, cols: number, rows: number): void {
         const terminal = this._terminals.get(id);
         if (terminal) {
             // resolve for existing clients
@@ -127,7 +131,7 @@ export class TerminalServiceExtImpl implements TerminalServiceExt {
             terminal.deferredProcessId = new Deferred<number>();
             terminal.deferredProcessId.resolve(processId);
         }
-        const pseudoTerminal = this._pseudoTerminals.get(id);
+        const pseudoTerminal = this._pseudoTerminals.get(terminalId.toString());
         if (pseudoTerminal) {
             pseudoTerminal.emitOnOpen(cols, rows);
         }
@@ -292,22 +296,36 @@ export class TerminalExtImpl implements Terminal {
 
 export class PseudoTerminal {
     constructor(
-        id: string,
+        id: string | number,
         private readonly proxy: TerminalServiceMain,
-        private readonly pseudoTerminal: theia.Pseudoterminal
+        private readonly pseudoTerminal: theia.Pseudoterminal,
+        waitOnExit?: boolean | string
     ) {
+
         pseudoTerminal.onDidWrite(data => {
-            this.proxy.$write(id, data);
+            if (typeof id === 'string') {
+                this.proxy.$write(id, data);
+            } else {
+                this.proxy.$writeByTerminalId(id, data);
+            }
         });
         if (pseudoTerminal.onDidClose) {
-            pseudoTerminal.onDidClose(() => {
-                this.proxy.$dispose(id);
+            pseudoTerminal.onDidClose((e: number | void = undefined) => {
+                if (typeof id === 'string') {
+                    this.proxy.$dispose(id);
+                } else {
+                    this.proxy.$disposeByTerminalId(id, waitOnExit);
+                }
             });
         }
         if (pseudoTerminal.onDidOverrideDimensions) {
             pseudoTerminal.onDidOverrideDimensions(e => {
                 if (e) {
-                    this.proxy.$resize(id, e.columns, e.rows);
+                    if (typeof id === 'string') {
+                        this.proxy.$resize(id, e.columns, e.rows);
+                    } else {
+                        this.proxy.$resizeByTerminalId(id, e.columns, e.rows);
+                    }
                 }
             });
         }
diff --git a/packages/plugin-ext/src/plugin/type-converters.ts b/packages/plugin-ext/src/plugin/type-converters.ts
index da2fb3ceacbf6..44b413d7bb4c1 100644
--- a/packages/plugin-ext/src/plugin/type-converters.ts
+++ b/packages/plugin-ext/src/plugin/type-converters.ts
@@ -758,6 +758,10 @@ export function fromTask(task: theia.Task): TaskDto | undefined {
         return fromProcessExecution(<theia.ProcessExecution>execution, taskDto);
     }
 
+    if (taskDefinition.type === 'customExecution' || types.CustomExecution.is(execution)) {
+        return fromCustomExecution(<theia.CustomExecution>execution, taskDto);
+    }
+
     return taskDto;
 }
 
@@ -800,6 +804,10 @@ export function toTask(taskDto: TaskDto): theia.Task {
         result.execution = getShellExecution(taskDto);
     }
 
+    if (taskType === 'customExecution' || types.CustomExecution.is(execution)) {
+        result.execution = getCustomExecution(taskDto);
+    }
+
     if (group) {
         if (group === BUILD_GROUP) {
             result.group = TaskGroup.Build;
@@ -858,6 +866,16 @@ export function fromShellExecution(execution: theia.ShellExecution, taskDto: Tas
     }
 }
 
+export function fromCustomExecution(execution: theia.CustomExecution, taskDto: TaskDto): TaskDto {
+    const callback = execution.callback;
+    if (callback) {
+        taskDto.callback = callback;
+        return taskDto;
+    } else {
+        throw new Error('Converting CustomExecution callback is not implemented');
+    }
+}
+
 export function getProcessExecution(taskDto: TaskDto): theia.ProcessExecution {
     return new types.ProcessExecution(
         taskDto.command,
@@ -877,6 +895,10 @@ export function getShellExecution(taskDto: TaskDto): theia.ShellExecution {
         taskDto.options || {});
 }
 
+export function getCustomExecution(taskDto: TaskDto): theia.CustomExecution {
+    return new types.CustomExecution(taskDto.callback);
+}
+
 export function getShellArgs(args: undefined | (string | theia.ShellQuotedString)[]): string[] {
     if (!args || args.length === 0) {
         return [];
diff --git a/packages/plugin-ext/src/plugin/types-impl.ts b/packages/plugin-ext/src/plugin/types-impl.ts
index 88e224f1a0215..76f54d87b5ce2 100644
--- a/packages/plugin-ext/src/plugin/types-impl.ts
+++ b/packages/plugin-ext/src/plugin/types-impl.ts
@@ -1543,7 +1543,7 @@ export class ProcessExecution {
         return computeTaskExecutionId(props);
     }
 
-    public static is(value: theia.ShellExecution | theia.ProcessExecution): boolean {
+    public static is(value: theia.ShellExecution | theia.ProcessExecution | theia.CustomExecution): boolean {
         const candidate = value as ProcessExecution;
         return candidate && !!candidate.process;
     }
@@ -1651,12 +1651,35 @@ export class ShellExecution {
         return computeTaskExecutionId(props);
     }
 
-    public static is(value: theia.ShellExecution | theia.ProcessExecution): boolean {
+    public static is(value: theia.ShellExecution | theia.ProcessExecution | theia.CustomExecution): boolean {
         const candidate = value as ShellExecution;
         return candidate && (!!candidate.commandLine || !!candidate.command);
     }
 }
 
+export class CustomExecution {
+    private _callback: (resolvedDefintion: theia.TaskDefinition) => Thenable<theia.Pseudoterminal>;
+    constructor(callback: (resolvedDefintion: theia.TaskDefinition) => Thenable<theia.Pseudoterminal>) {
+        this._callback = callback;
+    }
+    public computeId(): string {
+        return 'customExecution' + UUID.uuid4();
+    }
+
+    public set callback(value: (resolvedDefintion: theia.TaskDefinition) => Thenable<theia.Pseudoterminal>) {
+        this._callback = value;
+    }
+
+    public get callback(): ((resolvedDefintion: theia.TaskDefinition) => Thenable<theia.Pseudoterminal>) {
+        return this._callback;
+    }
+
+    public static is(value: theia.ShellExecution | theia.ProcessExecution | theia.CustomExecution): boolean {
+        const candidate = value as CustomExecution;
+        return candidate && (!!candidate._callback);
+    }
+}
+
 export class TaskGroup {
     private groupId: string;
 
@@ -1704,7 +1727,7 @@ export class Task {
     private taskDefinition: theia.TaskDefinition;
     private taskScope: theia.TaskScope.Global | theia.TaskScope.Workspace | theia.WorkspaceFolder | undefined;
     private taskName: string;
-    private taskExecution: ProcessExecution | ShellExecution | undefined;
+    private taskExecution: ProcessExecution | ShellExecution | CustomExecution | undefined;
     private taskProblemMatchers: string[];
     private hasTaskProblemMatchers: boolean;
     private isTaskBackground: boolean;
@@ -1716,7 +1739,7 @@ export class Task {
         scope: theia.WorkspaceFolder | theia.TaskScope.Global | theia.TaskScope.Workspace,
         name: string,
         source: string,
-        execution?: ProcessExecution | ShellExecution,
+        execution?: ProcessExecution | ShellExecution | CustomExecution,
         problemMatchers?: string | string[]
     );
 
@@ -1725,7 +1748,7 @@ export class Task {
         taskDefinition: theia.TaskDefinition,
         name: string,
         source: string,
-        execution?: ProcessExecution | ShellExecution,
+        execution?: ProcessExecution | ShellExecution | CustomExecution,
         problemMatchers?: string | string[],
     );
 
@@ -1735,7 +1758,7 @@ export class Task {
         let scope: theia.WorkspaceFolder | theia.TaskScope.Global | theia.TaskScope.Workspace | undefined;
         let name: string;
         let source: string;
-        let execution: ProcessExecution | ShellExecution | undefined;
+        let execution: ProcessExecution | ShellExecution | CustomExecution | undefined;
         let problemMatchers: string | string[] | undefined;
 
         if (typeof args[1] === 'string') {
@@ -1810,11 +1833,11 @@ export class Task {
         this.taskName = value;
     }
 
-    get execution(): ProcessExecution | ShellExecution | undefined {
+    get execution(): ProcessExecution | ShellExecution | CustomExecution | undefined {
         return this.taskExecution;
     }
 
-    set execution(value: ProcessExecution | ShellExecution | undefined) {
+    set execution(value: ProcessExecution | ShellExecution | CustomExecution | undefined) {
         if (value === null) {
             value = undefined;
         }
@@ -1898,6 +1921,18 @@ export class Task {
                 id: this.taskExecution.computeId(),
                 taskType: this.taskDefinition!.type
             });
+        } else if (this.taskExecution instanceof CustomExecution) {
+            Object.assign(this.taskDefinition, {
+                type: 'customExecution',
+                id: this.taskExecution.computeId(),
+                taskType: this.taskDefinition!.type
+            });
+        } else {
+            Object.assign(this.taskDefinition, {
+                type: '$empty',
+                id: UUID.uuid4(),
+                taskType: this.taskDefinition!.type
+            });
         }
     }
 }
diff --git a/packages/plugin/src/theia.d.ts b/packages/plugin/src/theia.d.ts
index dc2c67e7ee3ce..cba7376e81b18 100644
--- a/packages/plugin/src/theia.d.ts
+++ b/packages/plugin/src/theia.d.ts
@@ -9763,6 +9763,24 @@ declare module '@theia/plugin' {
         [name: string]: any;
     }
 
+    /**
+     * Class used to execute an extension callback as a task.
+     */
+    export class CustomExecution {
+        /**
+         * Constructs a CustomExecution task object. The callback will be executed when the task is run, at which point the
+         * extension should return the Pseudoterminal it will "run in". The task should wait to do further execution until
+         * [Pseudoterminal.open](#Pseudoterminal.open) is called. Task cancellation should be handled using
+         * [Pseudoterminal.close](#Pseudoterminal.close). When the task is complete fire
+         * [Pseudoterminal.onDidClose](#Pseudoterminal.onDidClose).
+         * @param callback The callback that will be called when the task is started by a user. Any ${} style variables that
+         * were in the task definition will be resolved and passed into the callback as `resolvedDefinition`.
+         */
+        constructor(callback: (resolvedDefinition: TaskDefinition) => Thenable<Pseudoterminal>);
+
+        readonly callback;
+    }
+
     export enum TaskScope {
         /** The task is a global task. Global tasks are currently not supported. */
         Global = 1,
@@ -9898,7 +9916,7 @@ declare module '@theia/plugin' {
         scope?: TaskScope.Global | TaskScope.Workspace | WorkspaceFolder;
 
         /** The task's execution engine */
-        execution?: ProcessExecution | ShellExecution;
+        execution?: ProcessExecution | ShellExecution | CustomExecution;
 
         /** Whether the task is a background task or not. */
         isBackground?: boolean;
diff --git a/packages/task/src/browser/task-service.ts b/packages/task/src/browser/task-service.ts
index 21b47f2e166af..7fb2e214c4a5c 100644
--- a/packages/task/src/browser/task-service.ts
+++ b/packages/task/src/browser/task-service.ts
@@ -450,6 +450,10 @@ export class TaskService implements TaskConfigurationClient {
         return this.taskServer.getTasks(this.getContext());
     }
 
+    async customExecutionComplete(id: number, exitCode: number | undefined): Promise<void> {
+        return this.taskServer.customExecutionComplete(id, exitCode);
+    }
+
     /** Returns an array of task types that are registered, including the default types */
     getRegisteredTaskTypes(): Promise<string[]> {
         return this.taskSchemaUpdater.getRegisteredTaskTypes();
diff --git a/packages/task/src/common/task-protocol.ts b/packages/task/src/common/task-protocol.ts
index 871386b6e2377..548851ec312ec 100644
--- a/packages/task/src/common/task-protocol.ts
+++ b/packages/task/src/common/task-protocol.ts
@@ -213,6 +213,8 @@ export interface TaskServer extends JsonRpcServer<TaskClient> {
     /** Returns the list of default and registered task runners */
     getRegisteredTaskTypes(): Promise<string[]>
 
+    /** plugin callback task complete */
+    customExecutionComplete(id: number, exitCode: number | undefined): Promise<void>
 }
 
 export interface TaskCustomizationData {
diff --git a/packages/task/src/node/custom/custom-task-runner-backend-module.ts b/packages/task/src/node/custom/custom-task-runner-backend-module.ts
new file mode 100644
index 0000000000000..63dc426a30426
--- /dev/null
+++ b/packages/task/src/node/custom/custom-task-runner-backend-module.ts
@@ -0,0 +1,37 @@
+/********************************************************************************
+ * Copyright (C) 2018 Red Hat, Inc. and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { interfaces, Container } from 'inversify';
+import { CustomTask, TaskFactory, TaskCustomOptions } from './custom-task';
+import { CustomTaskRunner } from './custom-task-runner';
+import { CustomTaskRunnerContribution } from './custom-task-runner-contribution';
+import { TaskRunnerContribution } from '../task-runner';
+
+export function bindCustomTaskRunnerModule(bind: interfaces.Bind): void {
+
+    bind(CustomTask).toSelf().inTransientScope();
+    bind(TaskFactory).toFactory(ctx =>
+        (options: TaskCustomOptions) => {
+            const child = new Container({ defaultScope: 'Singleton' });
+            child.parent = ctx.container;
+            child.bind(TaskCustomOptions).toConstantValue(options);
+            return child.get(CustomTask);
+        }
+    );
+    bind(CustomTaskRunner).toSelf().inSingletonScope();
+    bind(CustomTaskRunnerContribution).toSelf().inSingletonScope();
+    bind(TaskRunnerContribution).toService(CustomTaskRunnerContribution);
+}
diff --git a/packages/task/src/node/custom/custom-task-runner-contribution.ts b/packages/task/src/node/custom/custom-task-runner-contribution.ts
new file mode 100644
index 0000000000000..a15e76772d20e
--- /dev/null
+++ b/packages/task/src/node/custom/custom-task-runner-contribution.ts
@@ -0,0 +1,30 @@
+/********************************************************************************
+ * Copyright (C) 2018 Red Hat, Inc. and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { injectable, inject } from 'inversify';
+import { CustomTaskRunner } from './custom-task-runner';
+import { TaskRunnerContribution, TaskRunnerRegistry } from '../task-runner';
+
+@injectable()
+export class CustomTaskRunnerContribution implements TaskRunnerContribution {
+
+    @inject(CustomTaskRunner)
+    protected readonly customTaskRunner: CustomTaskRunner;
+
+    registerRunner(runners: TaskRunnerRegistry): void {
+        runners.registerRunner('customExecution', this.customTaskRunner);
+    }
+}
diff --git a/packages/task/src/node/custom/custom-task-runner.ts b/packages/task/src/node/custom/custom-task-runner.ts
new file mode 100644
index 0000000000000..427adee154e2c
--- /dev/null
+++ b/packages/task/src/node/custom/custom-task-runner.ts
@@ -0,0 +1,77 @@
+/********************************************************************************
+ * Copyright (C) 2017-2019 Ericsson and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { TaskConfiguration } from '../../common';
+import { Task } from '../task';
+import { TaskRunner } from '../task-runner';
+import { injectable, inject, named } from 'inversify';
+import { ILogger } from '@theia/core';
+import { TaskFactory } from './custom-task';
+import {
+    RawProcessFactory,
+    TerminalProcessFactory,
+    Process,
+    TerminalProcessOptions,
+} from '@theia/process/lib/node';
+
+/**
+ * Task runner that runs a task as a pseudoterminal open.
+ */
+@injectable()
+export class CustomTaskRunner implements TaskRunner {
+
+    @inject(ILogger) @named('task')
+    protected readonly logger: ILogger;
+
+    @inject(RawProcessFactory)
+    protected readonly rawProcessFactory: RawProcessFactory;
+
+    @inject(TerminalProcessFactory)
+    protected readonly terminalProcessFactory: TerminalProcessFactory;
+
+    @inject(TaskFactory)
+    protected readonly taskFactory: TaskFactory;
+
+    async run(tskConfig: TaskConfiguration, ctx?: string): Promise<Task> {
+        try {
+            const terminalProcessOptions = { isPseudo: true } as TerminalProcessOptions;
+            const terminal: Process = this.terminalProcessFactory(terminalProcessOptions);
+
+            // Wait for the confirmation that the process is successfully started, or has failed to start.
+            // await new Promise((resolve, reject) => {
+            //     terminal.onStart(resolve);
+            //     terminal.onError((error: ProcessErrorEvent) => {
+            //         reject(ProcessTaskError.CouldNotRun(error.code));
+            //     });
+            // });
+
+            return Promise.resolve(this.taskFactory({
+                context: ctx,
+                config: tskConfig,
+                label: tskConfig.label,
+                process: terminal,
+            }));
+        } catch (error) {
+            this.logger.error(`Error occurred while creating task: ${error}`);
+            throw error;
+        }
+    }
+}
diff --git a/packages/task/src/node/custom/custom-task.ts b/packages/task/src/node/custom/custom-task.ts
new file mode 100644
index 0000000000000..d1453a8f0fc77
--- /dev/null
+++ b/packages/task/src/node/custom/custom-task.ts
@@ -0,0 +1,78 @@
+/********************************************************************************
+ * Copyright (C) 2017 Ericsson and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+/*---------------------------------------------------------------------------------------------
+*  Copyright (c) Microsoft Corporation. All rights reserved.
+*  Licensed under the MIT License. See License.txt in the project root for license information.
+*--------------------------------------------------------------------------------------------*/
+
+import { injectable, inject, named } from 'inversify';
+import { ILogger, MaybePromise } from '@theia/core/lib/common/';
+import { Task, TaskOptions } from '../task';
+import { TaskManager } from '../task-manager';
+import { TaskInfo } from '../../common/task-protocol';
+import { Process } from '@theia/process/lib/node';
+
+export const TaskCustomOptions = Symbol('TaskCustomOptions');
+export interface TaskCustomOptions extends TaskOptions {
+    process: Process
+}
+
+export const TaskFactory = Symbol('TaskFactory');
+export type TaskFactory = (options: TaskCustomOptions) => CustomTask;
+
+/** Represents a Task launched as a fake process by `CustomTaskRunner`. */
+@injectable()
+export class CustomTask extends Task {
+
+    constructor(
+        @inject(TaskManager) protected readonly taskManager: TaskManager,
+        @inject(ILogger) @named('task') protected readonly logger: ILogger,
+        @inject(TaskCustomOptions) protected readonly options: TaskCustomOptions
+    ) {
+        super(taskManager, logger, options);
+        this.logger.info(`Created new custom task, id: ${this.id}, context: ${this.context}`);
+    }
+
+    kill(): Promise<void> {
+        return Promise.resolve();
+    }
+
+    getRuntimeInfo(): MaybePromise<TaskInfo> {
+        return {
+            taskId: this.id,
+            ctx: this.context,
+            config: this.options.config,
+            terminalId: this.process.id,
+            processId: this.process.id,
+        };
+    }
+
+    public callbackTaskComplete(exitCode: number | undefined): MaybePromise<void> {
+        this.fireTaskExited({
+            taskId: this.taskId,
+            ctx: this.context,
+            config: this.options.config,
+            terminalId: this.process.id,
+            processId: this.process.id,
+            code: exitCode,
+        });
+    }
+
+    get process(): Process {
+        return this.options.process;
+    }
+}
diff --git a/packages/task/src/node/task-backend-module.ts b/packages/task/src/node/task-backend-module.ts
index 77b0a709027b2..e92f8d06d6b0a 100644
--- a/packages/task/src/node/task-backend-module.ts
+++ b/packages/task/src/node/task-backend-module.ts
@@ -19,6 +19,7 @@ import { bindContributionProvider } from '@theia/core';
 import { ConnectionHandler, JsonRpcConnectionHandler } from '@theia/core/lib/common/messaging';
 import { BackendApplicationContribution } from '@theia/core/lib/node';
 import { bindProcessTaskRunnerModule } from './process/process-task-runner-backend-module';
+import { bindCustomTaskRunnerModule } from './custom/custom-task-runner-backend-module';
 import { TaskBackendApplicationContribution } from './task-backend-application-contribution';
 import { TaskManager } from './task-manager';
 import { TaskRunnerContribution, TaskRunnerRegistry } from './task-runner';
@@ -52,4 +53,5 @@ export default new ContainerModule(bind => {
     bind(BackendApplicationContribution).toService(TaskBackendApplicationContribution);
 
     bindProcessTaskRunnerModule(bind);
+    bindCustomTaskRunnerModule(bind);
 });
diff --git a/packages/task/src/node/task-server.ts b/packages/task/src/node/task-server.ts
index 8e7d8ca8ac665..376ac226a5a43 100644
--- a/packages/task/src/node/task-server.ts
+++ b/packages/task/src/node/task-server.ts
@@ -31,6 +31,7 @@ import { TaskRunnerRegistry } from './task-runner';
 import { Task } from './task';
 import { ProcessTask } from './process/process-task';
 import { ProblemCollector } from './task-problem-collector';
+import { CustomTask } from './custom/custom-task';
 
 @injectable()
 export class TaskServerImpl implements TaskServer, Disposable {
@@ -168,6 +169,12 @@ export class TaskServerImpl implements TaskServer, Disposable {
         return this.runnerRegistry.getRunnerTypes();
     }
 
+    async customExecutionComplete(id: number, exitCode: number | undefined): Promise<void> {
+        const task = this.taskManager.get(id) as CustomTask;
+        await task.callbackTaskComplete(exitCode);
+        return;
+    }
+
     protected fireTaskExitedEvent(event: TaskExitedEvent, task?: Task): void {
         this.logger.debug(log => log('task has exited:', event));
 
diff --git a/packages/terminal/src/browser/base/terminal-widget.ts b/packages/terminal/src/browser/base/terminal-widget.ts
index d2efff2c86247..a0f95911bcc1c 100644
--- a/packages/terminal/src/browser/base/terminal-widget.ts
+++ b/packages/terminal/src/browser/base/terminal-widget.ts
@@ -119,6 +119,8 @@ export abstract class TerminalWidget extends BaseWidget {
     abstract hasChildProcesses(): Promise<boolean>;
 
     abstract setTitle(title: string): void;
+
+    abstract waitOnExit(waitOnExit?: boolean | string): void;
 }
 
 /**
diff --git a/packages/terminal/src/browser/terminal-widget-impl.ts b/packages/terminal/src/browser/terminal-widget-impl.ts
index c4910bb1c6601..dee26879fa2db 100644
--- a/packages/terminal/src/browser/terminal-widget-impl.ts
+++ b/packages/terminal/src/browser/terminal-widget-impl.ts
@@ -36,7 +36,7 @@ import { TerminalSearchWidgetFactory, TerminalSearchWidget } from './search/term
 import { TerminalCopyOnSelectionHandler } from './terminal-copy-on-selection-handler';
 import { TerminalThemeService } from './terminal-theme-service';
 import { CommandLineOptions, ShellCommandBuilder } from '@theia/process/lib/common/shell-command-builder';
-
+import { Key } from '@theia/core/lib/browser/keys';
 export const TERMINAL_WIDGET_FACTORY_ID = 'terminal';
 
 export interface TerminalWidgetFactoryOptions extends Partial<TerminalWidgetOptions> {
@@ -670,4 +670,30 @@ export class TerminalWidgetImpl extends TerminalWidget implements StatefulWidget
         this.title.caption = title;
         this.title.label = title;
     }
+
+    waitOnExit(waitOnExit?: boolean | string): void {
+        if (waitOnExit) {
+            if (typeof waitOnExit === 'string') {
+                let message = waitOnExit;
+                // Bold the message and add an extra new line to make it stand out from the rest of the output
+                message = `\r\n\x1b[1m${message}\x1b[0m`;
+                this.write(message);
+            }
+            if (this.closeOnDispose === true && typeof this.terminalId === 'number') {
+                this.shellTerminalServer.close(this.terminalId);
+                this.onTermDidClose.fire(this);
+            }
+            this.attachPressAnyKeyToCloseListener(this.term);
+            return;
+        }
+        return this.dispose();
+    }
+
+    private attachPressAnyKeyToCloseListener(term: Terminal): void {
+        if (term.textarea) {
+            this.addKeyListener(term.textarea, Key.ENTER, (event: KeyboardEvent) => {
+                this.dispose();
+            });
+        }
+    }
 }