diff --git a/Lombiq.HelpfulLibraries.AspNetCore/Localization/LocalizedHtmlStringExtensions.cs b/Lombiq.HelpfulLibraries.AspNetCore/Localization/LocalizedHtmlStringExtensions.cs
index 5140451e..0ce75535 100644
--- a/Lombiq.HelpfulLibraries.AspNetCore/Localization/LocalizedHtmlStringExtensions.cs
+++ b/Lombiq.HelpfulLibraries.AspNetCore/Localization/LocalizedHtmlStringExtensions.cs
@@ -1,6 +1,8 @@
 using Microsoft.AspNetCore.Html;
 using Newtonsoft.Json;
 using System.IO;
+using System.Linq;
+using System.Text;
 using System.Text.Encodings.Web;
 
 namespace Microsoft.AspNetCore.Mvc.Localization;
@@ -29,4 +31,29 @@ public static string Html(this IHtmlContent htmlContent)
         htmlContent.WriteTo(stringWriter, HtmlEncoder.Default);
         return stringWriter.ToString();
     }
+
+    /// <summary>
+    /// Concatenates the <paramref name="first"/> localized HTML string with the <paramref name="other"/> provided HTML
+    /// content. This is suitable for joining individually localizable HTML strings.
+    /// </summary>
+    public static LocalizedHtmlString Concat(this LocalizedHtmlString first, params IHtmlContent[] other)
+    {
+        if (other.Length == 0) return first;
+
+        var builder = new StringBuilder(first.Html());
+        foreach (var content in other) builder.Append(content.Html());
+        var html = builder.ToString();
+
+        return new LocalizedHtmlString(html, html);
+    }
+
+    public static LocalizedHtmlString Join(this IHtmlContent separator, params LocalizedHtmlString[] items)
+    {
+        if (items.Length == 0) return null;
+
+        var first = items[0];
+        var other = items.Skip(1).SelectMany(item => new[] { separator, item }).ToArray();
+
+        return first.Concat(other);
+    }
 }
diff --git a/Lombiq.HelpfulLibraries.Common/Extensions/DictionaryExtensions.cs b/Lombiq.HelpfulLibraries.Common/Extensions/DictionaryExtensions.cs
index 1038e497..a3f081e4 100644
--- a/Lombiq.HelpfulLibraries.Common/Extensions/DictionaryExtensions.cs
+++ b/Lombiq.HelpfulLibraries.Common/Extensions/DictionaryExtensions.cs
@@ -1,3 +1,4 @@
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Threading.Tasks;
 
@@ -165,4 +166,101 @@ public static void AddToList<TKey, TValue>(
     /// </summary>
     public static IReadOnlyDictionary<TKey, TValue> ToReadOnly<TKey, TValue>(this IDictionary<TKey, TValue> dictionary) =>
         dictionary as IReadOnlyDictionary<TKey, TValue> ?? new Dictionary<TKey, TValue>(dictionary);
+
+    /// <summary>
+    /// Creates a new dictionary based on <paramref name="dictionary"/> by taking each entry's value, and if it's not
+    /// <see langword="null"/> and has at least one not <see langword="null"/> item then that item is added under the
+    /// same key.
+    /// </summary>
+    [SuppressMessage(
+        "Design",
+        "MA0016:Prefer returning collection abstraction instead of implementation",
+        Justification = "Better compatibility.")]
+    public static Dictionary<TKey, TValue> WithFirstValues<TKey, TValue, TValues>(
+        this IEnumerable<KeyValuePair<TKey, TValues>> dictionary,
+        Func<TValues, TValue> select = null)
+        where TValues : IEnumerable<TValue>
+    {
+        var result = new Dictionary<TKey, TValue>();
+
+        foreach (var (key, values) in dictionary)
+        {
+            if (select == null)
+            {
+                if (values is not null && values.FirstOrDefault() is { } value)
+                {
+                    result[key] = value;
+                }
+            }
+            else
+            {
+                if (select(values) is { } value)
+                {
+                    result[key] = value;
+                }
+            }
+        }
+
+        return result;
+    }
+
+    /// <summary>
+    /// Creates a new dictionary based on <paramref name="dictionary"/> where each value is a new instance of
+    /// <typeparamref name="TValues"/> which is an <see cref="IList{T}"/> of <typeparamref name="TValue"/>. If the value
+    /// is not <see langword="null"/> then it's added to the list.
+    /// </summary>
+    [SuppressMessage(
+        "Design",
+        "MA0016:Prefer returning collection abstraction instead of implementation",
+        Justification = "Better compatibility.")]
+    public static Dictionary<TKey, TValues> ToListValuedDictionary<TKey, TValue, TValues>(
+        this IEnumerable<KeyValuePair<TKey, TValue>> dictionary,
+        Func<TValue, TValues> select = null)
+        where TValues : IList<TValue>, new()
+    {
+        var result = new Dictionary<TKey, TValues>();
+
+        foreach (var (key, value) in dictionary)
+        {
+            if (select != null)
+            {
+                result[key] = select(value);
+                continue;
+            }
+
+            var list = new TValues();
+            if (value is not null) list.Add(value);
+            result[key] = list;
+        }
+
+        return result;
+    }
+
+    /// <summary>
+    /// Creates a new string keyed dictionary where the key is compared in a case-insensitive manner.
+    /// </summary>
+    public static IDictionary<string, TValue> ToDictionaryIgnoreCase<TValue>(
+        this IEnumerable<KeyValuePair<string, TValue>> source) =>
+        new Dictionary<string, TValue>(source, StringComparer.OrdinalIgnoreCase);
+
+    /// <summary>
+    /// Creates a new string keyed dictionary where the key is compared in a case-insensitive manner.
+    /// </summary>
+    public static IDictionary<string, TSource> ToDictionaryIgnoreCase<TSource>(
+        this IEnumerable<TSource> source,
+        Func<TSource, string> keySelector) =>
+        new Dictionary<string, TSource>(
+            source.Select(item => new KeyValuePair<string, TSource>(keySelector(item), item)),
+            StringComparer.OrdinalIgnoreCase);
+
+    /// <summary>
+    /// Creates a new string keyed dictionary where the key is compared in a case-insensitive manner.
+    /// </summary>
+    public static IDictionary<string, TValue> ToDictionaryIgnoreCase<TSource, TValue>(
+        this IEnumerable<TSource> source,
+        Func<TSource, string> keySelector,
+        Func<TSource, TValue> valueSelector) =>
+        new Dictionary<string, TValue>(
+            source.Select(item => new KeyValuePair<string, TValue>(keySelector(item), valueSelector(item))),
+            StringComparer.OrdinalIgnoreCase);
 }
diff --git a/Lombiq.HelpfulLibraries.OrchardCore/Contents/CommonContentDisplayTypes.cs b/Lombiq.HelpfulLibraries.OrchardCore/Contents/CommonContentDisplayTypes.cs
index c9c08ce6..10f3bea2 100644
--- a/Lombiq.HelpfulLibraries.OrchardCore/Contents/CommonContentDisplayTypes.cs
+++ b/Lombiq.HelpfulLibraries.OrchardCore/Contents/CommonContentDisplayTypes.cs
@@ -11,4 +11,5 @@ public static class CommonContentDisplayTypes
     public const string Detail = nameof(Detail);
     public const string Summary = nameof(Summary);
     public const string SummaryAdmin = nameof(SummaryAdmin);
+    public const string Thumbnail = nameof(Thumbnail);
 }
diff --git a/Lombiq.HelpfulLibraries.OrchardCore/Docs/Validation.md b/Lombiq.HelpfulLibraries.OrchardCore/Docs/Validation.md
new file mode 100644
index 00000000..494a017b
--- /dev/null
+++ b/Lombiq.HelpfulLibraries.OrchardCore/Docs/Validation.md
@@ -0,0 +1,5 @@
+# Lombiq Helpful Libraries - Orchard Core Libraries - Validation for Orchard Core
+
+## `IEmailAndPasswordValidator`
+
+A service for returning validation errors for email of password. Use its `ValidateEmailAsync` method to get email format validation errors, and its `ValidatePasswordAsync` to get validation errors from the registered `IPasswordValidator<IUser>` instances.
diff --git a/Lombiq.HelpfulLibraries.OrchardCore/Liquid/ILiquidContentDisplayService.cs b/Lombiq.HelpfulLibraries.OrchardCore/Liquid/ILiquidContentDisplayService.cs
new file mode 100644
index 00000000..d9d308eb
--- /dev/null
+++ b/Lombiq.HelpfulLibraries.OrchardCore/Liquid/ILiquidContentDisplayService.cs
@@ -0,0 +1,33 @@
+using Fluid.Values;
+using OrchardCore.DisplayManagement;
+using OrchardCore.DisplayManagement.Implementation;
+using System;
+using System.Threading.Tasks;
+
+namespace Lombiq.HelpfulLibraries.OrchardCore.Liquid;
+
+/// <summary>
+/// Service that displays shapes as HTML in a <see cref="FluidValue"/>.
+/// </summary>
+public interface ILiquidContentDisplayService
+{
+    /// <summary>
+    /// Creates new instances of a dynamic shape object and renders it to HTML in a <see cref="FluidValue"/>.
+    /// </summary>
+    ValueTask<FluidValue> DisplayShapeAsync(IShape shape);
+
+    /// <summary>
+    /// Creates new instances of a typed shape object and renders it to HTML in a <see cref="FluidValue"/>.
+    /// </summary>
+    /// <typeparam name="TModel">The type to instantiate.</typeparam>
+    ValueTask<FluidValue> DisplayNewAsync<TModel>(string shapeType, Action<TModel> initialize);
+
+    /// <summary>
+    /// Displays an already instantiated <see cref="IShape"/> as a <see cref="FluidValue"/>.
+    /// </summary>
+    ValueTask<FluidValue> DisplayNewAsync(
+        string shapeType,
+        Func<ValueTask<IShape>> shapeFactory,
+        Action<ShapeCreatingContext> creating = null,
+        Action<ShapeCreatedContext> created = null);
+}
diff --git a/Lombiq.HelpfulLibraries.OrchardCore/Liquid/LiquidContentDisplayService.cs b/Lombiq.HelpfulLibraries.OrchardCore/Liquid/LiquidContentDisplayService.cs
new file mode 100644
index 00000000..5cefd7ac
--- /dev/null
+++ b/Lombiq.HelpfulLibraries.OrchardCore/Liquid/LiquidContentDisplayService.cs
@@ -0,0 +1,41 @@
+using Fluid.Values;
+using OrchardCore.DisplayManagement;
+using OrchardCore.DisplayManagement.Implementation;
+using OrchardCore.DisplayManagement.Liquid;
+using System;
+using System.Threading.Tasks;
+
+namespace Lombiq.HelpfulLibraries.OrchardCore.Liquid;
+
+public class LiquidContentDisplayService : ILiquidContentDisplayService
+{
+    private readonly IDisplayHelper _displayHelper;
+    private readonly IShapeFactory _shapeFactory;
+    public LiquidContentDisplayService(IDisplayHelper displayHelper, IShapeFactory shapeFactory)
+    {
+        _displayHelper = displayHelper;
+        _shapeFactory = shapeFactory;
+    }
+
+    public async ValueTask<FluidValue> DisplayNewAsync(
+        string shapeType,
+        Func<ValueTask<IShape>> shapeFactory,
+        Action<ShapeCreatingContext> creating = null,
+        Action<ShapeCreatedContext> created = null)
+    {
+        var shape = await _shapeFactory.CreateAsync(shapeType, shapeFactory, creating, created);
+        return await DisplayShapeAsync(shape);
+    }
+
+    public async ValueTask<FluidValue> DisplayNewAsync<TModel>(string shapeType, Action<TModel> initialize)
+    {
+        var shape = await _shapeFactory.CreateAsync(shapeType, initialize);
+        return await DisplayShapeAsync(shape);
+    }
+
+    public async ValueTask<FluidValue> DisplayShapeAsync(IShape shape)
+    {
+        var content = await _displayHelper.ShapeExecuteAsync(shape);
+        return new HtmlContentValue(content);
+    }
+}
diff --git a/Lombiq.HelpfulLibraries.OrchardCore/Navigation/NavigationItemBuilderExtensions.cs b/Lombiq.HelpfulLibraries.OrchardCore/Navigation/NavigationItemBuilderExtensions.cs
index 1d83f587..5b71a0a2 100644
--- a/Lombiq.HelpfulLibraries.OrchardCore/Navigation/NavigationItemBuilderExtensions.cs
+++ b/Lombiq.HelpfulLibraries.OrchardCore/Navigation/NavigationItemBuilderExtensions.cs
@@ -60,4 +60,10 @@ public static NavigationBuilder AddSeparator(this NavigationBuilder builder, ISt
     /// </remarks>
     public static NavigationBuilder AddLabel(this NavigationBuilder builder, LocalizedString label) =>
         builder.Add(label, subMenu => subMenu.Url("#").AddClass("disabled menuWidget__link_label"));
+
+    /// <summary>
+    /// Adds a link to the menu item pointing to the site settings page identified by the <paramref name="groupId"/>.
+    /// </summary>
+    public static NavigationItemBuilder SiteSettings(this NavigationItemBuilder builder, string groupId) =>
+        builder.Action("Index", "Admin", new { area = "OrchardCore.Settings", groupId });
 }
diff --git a/Lombiq.HelpfulLibraries.OrchardCore/Validation/EmailAndPasswordValidator.cs b/Lombiq.HelpfulLibraries.OrchardCore/Validation/EmailAndPasswordValidator.cs
new file mode 100644
index 00000000..cc5d9663
--- /dev/null
+++ b/Lombiq.HelpfulLibraries.OrchardCore/Validation/EmailAndPasswordValidator.cs
@@ -0,0 +1,46 @@
+using Microsoft.AspNetCore.Identity;
+using Microsoft.Extensions.Localization;
+using OrchardCore.Email;
+using OrchardCore.Users;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Lombiq.HelpfulLibraries.OrchardCore.Validation;
+
+public class EmailAndPasswordValidator : IEmailAndPasswordValidator
+{
+    private readonly IEmailAddressValidator _emailAddressValidator;
+    private readonly UserManager<IUser> _userManager;
+    private readonly IStringLocalizer<EmailAndPasswordValidator> T;
+    public EmailAndPasswordValidator(
+        IEmailAddressValidator emailAddressValidator,
+        UserManager<IUser> userManager,
+        IStringLocalizer<EmailAndPasswordValidator> stringLocalizer)
+    {
+        _emailAddressValidator = emailAddressValidator;
+        _userManager = userManager;
+        T = stringLocalizer;
+    }
+
+    public Task<IEnumerable<LocalizedString>> ValidateEmailAsync(string email) =>
+        Task.FromResult(_emailAddressValidator.Validate(email)
+            ? Enumerable.Empty<LocalizedString>()
+            : new[] { T["Invalid email address."] });
+
+    public async Task<IEnumerable<LocalizedString>> ValidatePasswordAsync(string password)
+    {
+        var errors = new List<LocalizedString>();
+        if (password == null) return errors;
+
+        foreach (var passwordValidator in _userManager.PasswordValidators)
+        {
+            var result = await passwordValidator.ValidateAsync(_userManager, user: null, password);
+
+            if (result.Succeeded) continue;
+            errors.AddRange(result.Errors.Select(error => T[error.Description]));
+        }
+
+        return errors;
+    }
+}
diff --git a/Lombiq.HelpfulLibraries.OrchardCore/Validation/IEmailAndPasswordValidator.cs b/Lombiq.HelpfulLibraries.OrchardCore/Validation/IEmailAndPasswordValidator.cs
new file mode 100644
index 00000000..bc6bd600
--- /dev/null
+++ b/Lombiq.HelpfulLibraries.OrchardCore/Validation/IEmailAndPasswordValidator.cs
@@ -0,0 +1,21 @@
+using Microsoft.Extensions.Localization;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace Lombiq.HelpfulLibraries.OrchardCore.Validation;
+
+/// <summary>
+/// A service for returning validation errors for email of password.
+/// </summary>
+public interface IEmailAndPasswordValidator
+{
+    /// <summary>
+    /// Validates the provided <paramref name="email"/> and returns any validation errors as a localized string.
+    /// </summary>
+    Task<IEnumerable<LocalizedString>> ValidateEmailAsync(string email);
+
+    /// <summary>
+    /// Validates the provided <paramref name="password"/> and returns any validation errors as a localized string.
+    /// </summary>
+    Task<IEnumerable<LocalizedString>> ValidatePasswordAsync(string password);
+}