diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
index 6765d81a8b..fa22ca7a66 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.md
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -25,7 +25,7 @@ If applicable, add screenshots to help explain your problem.
 
 **Platform (please complete the following information):**
  - Supercomputer or desktop [e.g., Trinity, Sierra)
- - Compiler environment [e.g., clang-3.9, gcc8]
+ - Compiler environment [e.g., clang-4.0, gcc8]
  - Libraries [e.g., mpich-2, openmpi)
  - Commit ID or release of VT [e.g., vt-1.0.0]
 
diff --git a/.github/workflows/build-docs.yml b/.github/workflows/build-docs.yml
index aee70500e7..b748649fe9 100644
--- a/.github/workflows/build-docs.yml
+++ b/.github/workflows/build-docs.yml
@@ -18,7 +18,7 @@ jobs:
       ARCH: amd64
       UBUNTU: 18.04
       COMPILER_TYPE: gnu
-      COMPILER: gcc-5
+      COMPILER: gcc-7
       BUILD_TYPE: release
       ULIMIT_CORE: 0
       VT_LB: 1
diff --git a/README.md b/README.md
index c43a41e7bf..e39ef4d542 100644
--- a/README.md
+++ b/README.md
@@ -4,13 +4,10 @@
 [![codecov](https://codecov.io/gh/DARMA-tasking/vt/branch/develop/graph/badge.svg)](https://codecov.io/gh/DARMA-tasking/vt)
 [![License](https://img.shields.io/badge/License-BSD%203--Clause-orange.svg)](https://opensource.org/licenses/BSD-3-Clause)
 ![](https://github.com/DARMA-tasking/vt/workflows/Docker%20Image%20CI/badge.svg)
-[![gcc-5, ubuntu, mpich](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(gcc-5%2C%20ubuntu%2C%20mpich)?branchName=develop&Label=(gcc-5%2C%20ubuntu%2C%20mpich))](https://dev.azure.com/DARMA-tasking/DARMA/_build/latest?definitionId=2&branchName=develop)
-[![gcc-6, ubuntu, mpich](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(gcc-6%2C%20ubuntu%2C%20mpich)?branchName=develop&Label=(gcc-6%2C%20ubuntu%2C%20mpich))](https://dev.azure.com/DARMA-tasking/DARMA/_build/latest?definitionId=7&branchName=develop)
 [![gcc-7, ubuntu, mpich, trace runtime, LB](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(gcc-7%2C%20ubuntu%2C%20mpich%2C%20trace%20runtime%2C%20LB)?branchName=develop&Label=(gcc-7%2C%20ubuntu%2C%20mpich%2C%20trace%20runtime%2C%20LB))](https://dev.azure.com/DARMA-tasking/DARMA/_build/latest?definitionId=8&branchName=develop)
 [![gcc-8, ubuntu, mpich, address sanitizer](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(gcc-8%2C%20ubuntu%2C%20mpich%2C%20address%20sanitizer)?branchName=develop&Label=(gcc-8%2C%20ubuntu%2C%20mpich%2C%20address%20sanitizer))](https://dev.azure.com/DARMA-tasking/DARMA/_build/latest?definitionId=9&branchName=develop)
 [![gcc-9, ubuntu, mpich, zoltan](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(gcc-9%2C%20ubuntu%2C%20mpich%2C%20zoltan)?branchName=develop&Label=(gcc-9%2C%20ubuntu%2C%20mpich%2C%20zoltan))](https://dev.azure.com/DARMA-tasking/DARMA/_build/latest?definitionId=10&branchName=develop)
 [![gcc-10, ubuntu, openmpi, no LB](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(gcc-10%2C%20ubuntu%2C%20openmpi%2C%20no%20LB)?branchName=develop&Label=(gcc-10%2C%20ubuntu%2C%20openmpi%2C%20no%20LB))](https://dev.azure.com/DARMA-tasking/DARMA/_build/latest?definitionId=4&branchName=develop)
-[![clang-3.9, ubuntu, mpich](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(clang-3.9%2C%20ubuntu%2C%20mpich)?branchName=develop&Label=(clang-3.9%2C%20ubuntu%2C%20mpich))](https://dev.azure.com/DARMA-tasking/DARMA/_build/latest?definitionId=3&branchName=develop)
 [![clang-5, ubuntu, mpich, trace](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(clang-5.0%2C%20ubuntu%2C%20mpich)?branchName=develop&Label=(clang-5.0%2C%20ubuntu%2C%20mpich))](https://dev.azure.com/DARMA-tasking/DARMA/_build/latest?definitionId=5&branchName=develop)
 [![clang-9, ubuntu, mpich](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(clang-9%2C%20ubuntu%2C%20mpich)?branchName=develop&Label=(clang-9.0%2C%20ubuntu%2C%20mpich))](https://dev.azure.com/DARMA-tasking/DARMA/_build?definitionId=22&branchName=develop)
 [![clang-10, ubuntu, mpich](https://dev.azure.com/DARMA-tasking/DARMA/_apis/build/status/PR%20tests%20(clang-10%2C%20ubuntu%2C%20mpich)?branchName=develop&Label=(clang-10.0%2C%20ubuntu%2C%20mpich))](https://dev.azure.com/DARMA-tasking/DARMA/_build?definitionId=21&branchName=develop)
diff --git a/ci/azure/azure-clang-3.9-ubuntu-mpich.yml b/ci/azure/azure-clang-3.9-ubuntu-mpich.yml
deleted file mode 100644
index 6e5d0f410a..0000000000
--- a/ci/azure/azure-clang-3.9-ubuntu-mpich.yml
+++ /dev/null
@@ -1,211 +0,0 @@
-###############################################################################
-############## Warning this is a generated file---do not modify ###############
-###############################################################################
-
-name: PR tests (clang-3.9, ubuntu, mpich)
-
-trigger:
-  branches:
-    include:
-      - develop
-      - 1.0.0*
-
-pr:
-  drafts: false
-  autoCancel: true
-  branches:
-    include:
-      - '*'
-
-
-resources:
-- repo: self
-
-variables:
-  tag: '$(Build.BuildId)'
-  REPO: lifflander1/vt
-  ARCH: amd64
-  UBUNTU: 18.04
-  COMPILER_TYPE: clang
-  COMPILER: clang-3.9
-  BUILD_TYPE: release
-  ULIMIT_CORE: 0
-  CODE_COVERAGE: 0
-  VT_LB: 1
-  VT_TRACE: 0
-  VT_TRACE_RT: 0
-  VT_TRACE_ONLY: 1
-  VT_MIMALLOC: 0
-  VT_DOCS: 0
-  VT_ASAN: 0
-  VT_UBSAN: 0
-  VT_WERROR: 1
-  VT_POOL: 1
-  VT_EXTENDED_TESTS: 1
-  VT_TESTS_NUM_NODES: 2
-  VT_UNITY_BUILD: 1
-  VT_PRODUCTION_BUILD: 1
-  VT_FCONTEXT: 1
-  VT_USE_OPENMP: 0
-  VT_USE_STD_THREAD: 0
-  VT_ZOLTAN: 0
-  VT_CI_BUILD: 1
-  VT_DIAGNOSTICS: 1
-  VT_NO_COLOR: 1
-  VT_BUILD_SHARED_LIBS: 0
-  VT_INCLUSION: TPL
-  CMAKE_CXX_STANDARD: 14
-  TEST_LB_SCHEMA: 0
-  CACHE: "$(Agent.TempDirectory)/cache/"
-  cache_name: ubuntu-clang-3.9-cache
-  build_root: "$(CACHE)/$(ARCH)-ubuntu-$(UBUNTU)-$(COMPILER)-cache/"
-  TS: 0
-  TS_YEAR: 0
-  TS_MONTH: 0
-  TS_DAY: 0
-
-
-
-stages:
-- stage: Build
-  displayName: Build image
-  jobs:
-  - job: Build
-    displayName: Build
-    pool:
-      vmImage: 'ubuntu-22.04'
-    timeoutInMinutes: 180
-    steps:
-      - task: Bash@3
-        displayName: Job setup
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo setup
-      - task: Bash@3
-        displayName: Build timestamp for caching
-        continueOnError: true
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo 'string(TIMESTAMP current_date "%H;%M;%S" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS]$val"
-            echo 'string(TIMESTAMP current_date "%Y" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_YEAR]$val"
-            echo 'string(TIMESTAMP current_date "%m" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_MONTH]$val"
-            echo 'string(TIMESTAMP current_date "%d" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_DAY]$val"
-      - task: Bash@3
-        displayName: Output timestamp for caching
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: 'echo "my pipeline variable is $(TS) $(TS_YEAR) $(TS_MONTH) $(TS_DAY)"'
-      - task: Cache@2
-        displayName: Update cache
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          securityNamespace: cache
-          key: $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH) | $(TS_DAY) | $(TS)
-          path: '$(build_root)/ccache'
-          restoreKeys: |
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH) | $(TS_DAY)
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH)
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR)
-            $(Agent.OS) | "$(cache_name)"
-      - task: Bash@3
-        displayName: Check for changes in containers
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            val=$(./scripts/check_containers.sh)
-            echo "##vso[task.setvariable variable=compose_command]$val"
-      - task: DockerCompose@0
-        displayName: Pull container
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: '$(compose_command) ubuntu-cpp-clean'
-      - task: DockerCompose@0
-        displayName: Build container
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: 'run ubuntu-cpp-clean'
-        env:
-          CODECOV_TOKEN: $(codecov_token)
-      - task: Bash@3
-        displayName: Put compilation's and tests' logs in PR comment
-        continueOnError: true
-        condition: and(succeededOrFailed(), eq(variables['Build.Reason'], 'PullRequest'))
-        inputs:
-          targetType: 'inline'
-          script: |
-            ./scripts/report_logs_in_comment.sh                     \
-                "$(build_root)/vt/compilation_errors_warnings.out"  \
-                "$(build_root)/vt/cmake-output.log"                 \
-                "$(Build.BuildNumber)"                              \
-                "$(System.PullRequest.PullRequestNumber)"           \
-                "$(Build.Repository.Name)"                          \
-                "$GITHUB_PAT"                                       \
-                "$(Build.BuildId)"                                  \
-                "$(System.JobId)"                                   \
-                "$(Agent.JobStatus)"
-        env:
-          GITHUB_PAT: $(github_pat)
-      - task: DockerCompose@0
-        displayName: Push container to registry
-        continueOnError: true
-        condition: and(succeeded(), eq(variables['Build.SourceBranch'], 'refs/heads/develop'))
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerRegistryEndpoint: 'dockerRegistryConnection1'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: 'push ubuntu-cpp-clean'
-      - task: Bash@3
-        displayName: Create artifacts
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            zip -j $(Agent.TempDirectory)/LastTest.log.gz $(build_root)/vt/Testing/Temporary/LastTest.log
-            zip -j $(Agent.TempDirectory)/cmake-output.log.gz $(build_root)/vt/cmake-output.log
-      - task: PublishPipelineArtifact@1
-        displayName: Upload CMake test output artifact
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetPath: '$(Agent.TempDirectory)/LastTest.log.gz'
-          artifact: 'CMakeLastTestLog'
-          publishLocation: 'pipeline'
-      - task: PublishPipelineArtifact@1
-        displayName: Upload CMake full output artifact
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetPath: '$(Agent.TempDirectory)/cmake-output.log.gz'
-          artifact: 'CMakeOutputLog'
-          publishLocation: 'pipeline'
-      - task: Bash@3
-        displayName: Finish pipeline
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo Done
diff --git a/ci/azure/azure-gcc-5-ubuntu-mpich.yml b/ci/azure/azure-gcc-5-ubuntu-mpich.yml
deleted file mode 100644
index 5070c3f356..0000000000
--- a/ci/azure/azure-gcc-5-ubuntu-mpich.yml
+++ /dev/null
@@ -1,211 +0,0 @@
-###############################################################################
-############## Warning this is a generated file---do not modify ###############
-###############################################################################
-
-name: PR tests (gcc-5, ubuntu, mpich)
-
-trigger:
-  branches:
-    include:
-      - develop
-      - 1.0.0*
-
-pr:
-  drafts: false
-  autoCancel: true
-  branches:
-    include:
-      - '*'
-
-
-resources:
-- repo: self
-
-variables:
-  tag: '$(Build.BuildId)'
-  REPO: lifflander1/vt
-  ARCH: amd64
-  UBUNTU: 18.04
-  COMPILER_TYPE: gnu
-  COMPILER: gcc-5
-  BUILD_TYPE: release
-  ULIMIT_CORE: 0
-  CODE_COVERAGE: 0
-  VT_LB: 1
-  VT_TRACE: 0
-  VT_TRACE_RT: 0
-  VT_TRACE_ONLY: 1
-  VT_MIMALLOC: 0
-  VT_DOCS: 0
-  VT_ASAN: 0
-  VT_UBSAN: 0
-  VT_WERROR: 1
-  VT_POOL: 1
-  VT_EXTENDED_TESTS: 1
-  VT_TESTS_NUM_NODES: 2
-  VT_UNITY_BUILD: 1
-  VT_PRODUCTION_BUILD: 0
-  VT_FCONTEXT: 0
-  VT_USE_OPENMP: 1
-  VT_USE_STD_THREAD: 0
-  VT_ZOLTAN: 0
-  VT_CI_BUILD: 1
-  VT_DIAGNOSTICS: 1
-  VT_NO_COLOR: 1
-  VT_BUILD_SHARED_LIBS: 0
-  VT_INCLUSION: TPL
-  CMAKE_CXX_STANDARD: 14
-  TEST_LB_SCHEMA: 0
-  CACHE: "$(Agent.TempDirectory)/cache/"
-  cache_name: ubuntu-gcc-5-cache
-  build_root: "$(CACHE)/$(ARCH)-ubuntu-$(UBUNTU)-$(COMPILER)-cache/"
-  TS: 0
-  TS_YEAR: 0
-  TS_MONTH: 0
-  TS_DAY: 0
-
-
-
-stages:
-- stage: Build
-  displayName: Build image
-  jobs:
-  - job: Build
-    displayName: Build
-    pool:
-      vmImage: 'ubuntu-22.04'
-    timeoutInMinutes: 180
-    steps:
-      - task: Bash@3
-        displayName: Job setup
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo setup
-      - task: Bash@3
-        displayName: Build timestamp for caching
-        continueOnError: true
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo 'string(TIMESTAMP current_date "%H;%M;%S" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS]$val"
-            echo 'string(TIMESTAMP current_date "%Y" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_YEAR]$val"
-            echo 'string(TIMESTAMP current_date "%m" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_MONTH]$val"
-            echo 'string(TIMESTAMP current_date "%d" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_DAY]$val"
-      - task: Bash@3
-        displayName: Output timestamp for caching
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: 'echo "my pipeline variable is $(TS) $(TS_YEAR) $(TS_MONTH) $(TS_DAY)"'
-      - task: Cache@2
-        displayName: Update cache
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          securityNamespace: cache
-          key: $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH) | $(TS_DAY) | $(TS)
-          path: '$(build_root)/ccache'
-          restoreKeys: |
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH) | $(TS_DAY)
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH)
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR)
-            $(Agent.OS) | "$(cache_name)"
-      - task: Bash@3
-        displayName: Check for changes in containers
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            val=$(./scripts/check_containers.sh)
-            echo "##vso[task.setvariable variable=compose_command]$val"
-      - task: DockerCompose@0
-        displayName: Pull container
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: '$(compose_command) ubuntu-cpp-clean'
-      - task: DockerCompose@0
-        displayName: Build container
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: 'run ubuntu-cpp-clean'
-        env:
-          CODECOV_TOKEN: $(codecov_token)
-      - task: Bash@3
-        displayName: Put compilation's and tests' logs in PR comment
-        continueOnError: true
-        condition: and(succeededOrFailed(), eq(variables['Build.Reason'], 'PullRequest'))
-        inputs:
-          targetType: 'inline'
-          script: |
-            ./scripts/report_logs_in_comment.sh                     \
-                "$(build_root)/vt/compilation_errors_warnings.out"  \
-                "$(build_root)/vt/cmake-output.log"                 \
-                "$(Build.BuildNumber)"                              \
-                "$(System.PullRequest.PullRequestNumber)"           \
-                "$(Build.Repository.Name)"                          \
-                "$GITHUB_PAT"                                       \
-                "$(Build.BuildId)"                                  \
-                "$(System.JobId)"                                   \
-                "$(Agent.JobStatus)"
-        env:
-          GITHUB_PAT: $(github_pat)
-      - task: DockerCompose@0
-        displayName: Push container to registry
-        continueOnError: true
-        condition: and(succeeded(), eq(variables['Build.SourceBranch'], 'refs/heads/develop'))
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerRegistryEndpoint: 'dockerRegistryConnection1'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: 'push ubuntu-cpp-clean'
-      - task: Bash@3
-        displayName: Create artifacts
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            zip -j $(Agent.TempDirectory)/LastTest.log.gz $(build_root)/vt/Testing/Temporary/LastTest.log
-            zip -j $(Agent.TempDirectory)/cmake-output.log.gz $(build_root)/vt/cmake-output.log
-      - task: PublishPipelineArtifact@1
-        displayName: Upload CMake test output artifact
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetPath: '$(Agent.TempDirectory)/LastTest.log.gz'
-          artifact: 'CMakeLastTestLog'
-          publishLocation: 'pipeline'
-      - task: PublishPipelineArtifact@1
-        displayName: Upload CMake full output artifact
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetPath: '$(Agent.TempDirectory)/cmake-output.log.gz'
-          artifact: 'CMakeOutputLog'
-          publishLocation: 'pipeline'
-      - task: Bash@3
-        displayName: Finish pipeline
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo Done
diff --git a/ci/azure/azure-gcc-6-ubuntu-mpich.yml b/ci/azure/azure-gcc-6-ubuntu-mpich.yml
deleted file mode 100644
index 73f6eb0666..0000000000
--- a/ci/azure/azure-gcc-6-ubuntu-mpich.yml
+++ /dev/null
@@ -1,211 +0,0 @@
-###############################################################################
-############## Warning this is a generated file---do not modify ###############
-###############################################################################
-
-name: PR tests (gcc-6, ubuntu, mpich)
-
-trigger:
-  branches:
-    include:
-      - develop
-      - 1.0.0*
-
-pr:
-  drafts: false
-  autoCancel: true
-  branches:
-    include:
-      - '*'
-
-
-resources:
-- repo: self
-
-variables:
-  tag: '$(Build.BuildId)'
-  REPO: lifflander1/vt
-  ARCH: amd64
-  UBUNTU: 18.04
-  COMPILER_TYPE: gnu
-  COMPILER: gcc-6
-  BUILD_TYPE: release
-  ULIMIT_CORE: 0
-  CODE_COVERAGE: 0
-  VT_LB: 1
-  VT_TRACE: 0
-  VT_TRACE_RT: 0
-  VT_TRACE_ONLY: 1
-  VT_MIMALLOC: 0
-  VT_DOCS: 0
-  VT_ASAN: 0
-  VT_UBSAN: 0
-  VT_WERROR: 1
-  VT_POOL: 1
-  VT_EXTENDED_TESTS: 1
-  VT_TESTS_NUM_NODES: 2
-  VT_UNITY_BUILD: 0
-  VT_PRODUCTION_BUILD: 1
-  VT_FCONTEXT: 1
-  VT_USE_OPENMP: 0
-  VT_USE_STD_THREAD: 0
-  VT_ZOLTAN: 0
-  VT_CI_BUILD: 1
-  VT_DIAGNOSTICS: 1
-  VT_NO_COLOR: 1
-  VT_BUILD_SHARED_LIBS: 0
-  VT_INCLUSION: TPL
-  CMAKE_CXX_STANDARD: 14
-  TEST_LB_SCHEMA: 0
-  CACHE: "$(Agent.TempDirectory)/cache/"
-  cache_name: ubuntu-gcc-6-cache
-  build_root: "$(CACHE)/$(ARCH)-ubuntu-$(UBUNTU)-$(COMPILER)-cache/"
-  TS: 0
-  TS_YEAR: 0
-  TS_MONTH: 0
-  TS_DAY: 0
-
-
-
-stages:
-- stage: Build
-  displayName: Build image
-  jobs:
-  - job: Build
-    displayName: Build
-    pool:
-      vmImage: 'ubuntu-22.04'
-    timeoutInMinutes: 180
-    steps:
-      - task: Bash@3
-        displayName: Job setup
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo setup
-      - task: Bash@3
-        displayName: Build timestamp for caching
-        continueOnError: true
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo 'string(TIMESTAMP current_date "%H;%M;%S" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS]$val"
-            echo 'string(TIMESTAMP current_date "%Y" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_YEAR]$val"
-            echo 'string(TIMESTAMP current_date "%m" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_MONTH]$val"
-            echo 'string(TIMESTAMP current_date "%d" UTC)' > script
-            echo 'execute_process(COMMAND ${CMAKE_COMMAND} -E echo "${current_date}")' >> script
-            val=$(cmake -P script)
-            echo "##vso[task.setvariable variable=TS_DAY]$val"
-      - task: Bash@3
-        displayName: Output timestamp for caching
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: 'echo "my pipeline variable is $(TS) $(TS_YEAR) $(TS_MONTH) $(TS_DAY)"'
-      - task: Cache@2
-        displayName: Update cache
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          securityNamespace: cache
-          key: $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH) | $(TS_DAY) | $(TS)
-          path: '$(build_root)/ccache'
-          restoreKeys: |
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH) | $(TS_DAY)
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR) | $(TS_MONTH)
-            $(Agent.OS) | "$(cache_name)" | $(TS_YEAR)
-            $(Agent.OS) | "$(cache_name)"
-      - task: Bash@3
-        displayName: Check for changes in containers
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            val=$(./scripts/check_containers.sh)
-            echo "##vso[task.setvariable variable=compose_command]$val"
-      - task: DockerCompose@0
-        displayName: Pull container
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: '$(compose_command) ubuntu-cpp-clean'
-      - task: DockerCompose@0
-        displayName: Build container
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: 'run ubuntu-cpp-clean'
-        env:
-          CODECOV_TOKEN: $(codecov_token)
-      - task: Bash@3
-        displayName: Put compilation's and tests' logs in PR comment
-        continueOnError: true
-        condition: and(succeededOrFailed(), eq(variables['Build.Reason'], 'PullRequest'))
-        inputs:
-          targetType: 'inline'
-          script: |
-            ./scripts/report_logs_in_comment.sh                     \
-                "$(build_root)/vt/compilation_errors_warnings.out"  \
-                "$(build_root)/vt/cmake-output.log"                 \
-                "$(Build.BuildNumber)"                              \
-                "$(System.PullRequest.PullRequestNumber)"           \
-                "$(Build.Repository.Name)"                          \
-                "$GITHUB_PAT"                                       \
-                "$(Build.BuildId)"                                  \
-                "$(System.JobId)"                                   \
-                "$(Agent.JobStatus)"
-        env:
-          GITHUB_PAT: $(github_pat)
-      - task: DockerCompose@0
-        displayName: Push container to registry
-        continueOnError: true
-        condition: and(succeeded(), eq(variables['Build.SourceBranch'], 'refs/heads/develop'))
-        inputs:
-          containerregistrytype: 'Container Registry'
-          dockerRegistryEndpoint: 'dockerRegistryConnection1'
-          dockerComposeFile: '**/docker-compose.yml'
-          action: 'Run a Docker Compose command'
-          dockerComposeCommand: 'push ubuntu-cpp-clean'
-      - task: Bash@3
-        displayName: Create artifacts
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            zip -j $(Agent.TempDirectory)/LastTest.log.gz $(build_root)/vt/Testing/Temporary/LastTest.log
-            zip -j $(Agent.TempDirectory)/cmake-output.log.gz $(build_root)/vt/cmake-output.log
-      - task: PublishPipelineArtifact@1
-        displayName: Upload CMake test output artifact
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetPath: '$(Agent.TempDirectory)/LastTest.log.gz'
-          artifact: 'CMakeLastTestLog'
-          publishLocation: 'pipeline'
-      - task: PublishPipelineArtifact@1
-        displayName: Upload CMake full output artifact
-        continueOnError: true
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetPath: '$(Agent.TempDirectory)/cmake-output.log.gz'
-          artifact: 'CMakeOutputLog'
-          publishLocation: 'pipeline'
-      - task: Bash@3
-        displayName: Finish pipeline
-        condition: in(variables['Agent.JobStatus'], 'Succeeded', 'SucceededWithIssues')
-        inputs:
-          targetType: 'inline'
-          script: |
-            echo Done
diff --git a/docker-compose.yml b/docker-compose.yml
index 7401ae4ae8..08a5d240dc 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -10,8 +10,8 @@
 # Variables:
 #   ARCH={amd64, arm64v8, ...}
 #   COMPILER_TYPE={gnu, clang, intel, nvidia}
-#   COMPILER={gcc-5, gcc-6, gcc-7, gcc-8, gcc-9, gcc-10,
-#             clang-3.9, clang-4.0, clang-5.0, clang-6.0, clang-7, clang-8,
+#   COMPILER={gcc-7, gcc-8, gcc-9, gcc-10,
+#             clang-4.0, clang-5.0, clang-6.0, clang-7, clang-8,
 #             clang-9, clang-10,
 #             icpx,
 #             nvcc-10, nvcc-10.2, nvcc-11}
@@ -72,7 +72,6 @@ version: '3.5'
 # add it to this list. For example, for ARM64v8 on Ubuntu 20.04 with clang-9,
 # add `arm64v8-ubuntu-20.04-clang-9-cache`.
 volumes:
-  amd64-ubuntu-18.04-clang-3.9-cache:
   amd64-ubuntu-18.04-clang-4.0-cache:
   amd64-ubuntu-18.04-clang-5.0-cache:
   amd64-ubuntu-18.04-clang-6.0-cache:
@@ -81,8 +80,6 @@ volumes:
   amd64-ubuntu-18.04-clang-9-cache:
   amd64-ubuntu-20.04-clang-10-cache:
   amd64-ubuntu-22.04-clang-11-cache:
-  amd64-ubuntu-18.04-gcc-5-cache:
-  amd64-ubuntu-18.04-gcc-6-cache:
   amd64-ubuntu-18.04-gcc-7-cache:
   amd64-ubuntu-18.04-gcc-8-cache:
   amd64-ubuntu-20.04-gcc-9-cache:
@@ -92,7 +89,6 @@ volumes:
   amd64-ubuntu-18.04-nvcc-10-cache:
   amd64-ubuntu-18.04-nvcc-10.2-cache:
   amd64-ubuntu-18.04-nvcc-11-cache:
-  amd64-alpine-clang-3.9-cache:
   amd64-alpine-clang-4.0-cache:
   amd64-alpine-clang-5.0-cache:
   amd64-alpine-clang-6.0-cache:
@@ -101,8 +97,6 @@ volumes:
   amd64-alpine-clang-9-cache:
   amd64-alpine-clang-10-cache:
   amd64-alpine-clang-11-cache:
-  amd64-alpine-gcc-5-cache:
-  amd64-alpine-gcc-6-cache:
   amd64-alpine-gcc-7-cache:
   amd64-alpine-gcc-8-cache:
   amd64-alpine-gcc-9-cache:
diff --git a/docs/md/building.md b/docs/md/building.md
index 9df24ac154..60728d090f 100644
--- a/docs/md/building.md
+++ b/docs/md/building.md
@@ -150,8 +150,8 @@ which `docker-compose` will read.
 # Variables:
 #   ARCH={amd64, arm64v8, ...}
 #   COMPILER_TYPE={gnu, clang, intel, nvidia}
-#   COMPILER={gcc-5, gcc-6, gcc-7, gcc-8, gcc-9, gcc-10,
-#             clang-3.9, clang-4.0, clang-5.0, clang-6.0, clang-7, clang-8,
+#   COMPILER={gcc-7, gcc-8, gcc-9, gcc-10,
+#             clang-4.0, clang-5.0, clang-6.0, clang-7, clang-8,
 #             clang-9, clang-10,
 #             icc-18, icc-19,
 #             nvcc-10, nvcc-11}