diff --git a/.github/workflows/CI-CD.yml b/.github/workflows/CI-CD.yml
index eccc67d9..3e6030c6 100644
--- a/.github/workflows/CI-CD.yml
+++ b/.github/workflows/CI-CD.yml
@@ -25,16 +25,29 @@ jobs:
         os: [windows-latest, ubuntu-latest]
     runs-on: ${{ matrix.os }}
 
+    env:
+      DOTNET_INSTALL_DIR: "./.dotnet"
+  
     steps:
     - name: Checkout
       uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       with:
         fetch-depth: '0'
 
+    - name: Install Mono (Linux only)
+      if: matrix.os == 'ubuntu-latest'
+      run: |
+        sudo apt update
+        sudo apt install -y mono-complete
+
     - name: Install .NET Core
       uses: actions/setup-dotnet@3e891b0cb619bf60e2c25674b222b8940e2c1c25 # v4.1.0
       with:
         dotnet-version: 6.0.x
+        
+    - name: Add .NET to PATH (Linux only)
+      if: matrix.os == 'ubuntu-latest'
+      run: echo "$DOTNET_INSTALL_DIR:$DOTNET_INSTALL_DIR/tools" >> $GITHUB_PATH
 
     - name: Set up Visual Studio shell
       uses: egor-tensin/vs-shell@9a932a62d05192eae18ca370155cf877eecc2202 # v2
diff --git a/SIL.BuildTasks/UnitTestTasks/NUnit3.cs b/SIL.BuildTasks/UnitTestTasks/NUnit3.cs
index 08036c4d..02f4eee5 100644
--- a/SIL.BuildTasks/UnitTestTasks/NUnit3.cs
+++ b/SIL.BuildTasks/UnitTestTasks/NUnit3.cs
@@ -4,7 +4,6 @@
 using System;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
-using System.IO;
 using System.Text;
 
 namespace SIL.BuildTasks.UnitTestTasks
diff --git a/SIL.ReleaseTasks.Tests/CreateReleaseNotesHtmlTests.cs b/SIL.ReleaseTasks.Tests/CreateReleaseNotesHtmlTests.cs
index 62d3bdfa..f193a18c 100644
--- a/SIL.ReleaseTasks.Tests/CreateReleaseNotesHtmlTests.cs
+++ b/SIL.ReleaseTasks.Tests/CreateReleaseNotesHtmlTests.cs
@@ -1,54 +1,67 @@
-// Copyright (c) 2018 SIL Global
+// Copyright (c) 2018-2025 SIL Global
 // This software is licensed under the MIT License (http://opensource.org/licenses/MIT)
 
+using System;
+using System.Collections.Generic;
 using System.IO;
 using NUnit.Framework;
+using static System.IO.Path;
 
 namespace SIL.ReleaseTasks.Tests
 {
 	[TestFixture]
 	public class CreateReleaseNotesHtmlTests
 	{
+		private const string kNotReleaseNotesClassName = "notmarkdown";
+		private static readonly string NotReleaseNotesDiv =
+			$"<div class='{kNotReleaseNotesClassName}'/>";
+		private static readonly string NotReleaseNotesDivXpath =
+			$"//div[contains(@class, '{kNotReleaseNotesClassName}')]";
+		private static readonly string ReleaseNotesClassAttribute =
+			$"class='{CreateReleaseNotesHtml.kReleaseNotesClassName}'";
+
+		private static string GetRandomFileEndingWith(string ending) => Combine(GetTempPath(), GetRandomFileName() + ending);
+
 		[Test]
 		public void MissingMarkdownReturnsFalse()
 		{
 			var mockEngine = new MockEngine();
-			var testMarkdown = new CreateReleaseNotesHtml();
-			testMarkdown.ChangelogFile = Path.GetRandomFileName();
-			testMarkdown.BuildEngine = mockEngine;
-			Assert.That(testMarkdown.Execute(), Is.False);
+			var sut = new CreateReleaseNotesHtml
+			{
+				ChangelogFile = GetRandomFileName(),
+				BuildEngine = mockEngine
+			};
+			Assert.That(sut.Execute(), Is.False);
 			Assert.That(mockEngine.LoggedMessages[0], Does.StartWith("The given markdown file (").And.EndsWith(") does not exist."));
 		}
 
 		[Test]
 		public void SimpleMdResultsInSimpleHtml()
 		{
-			var testMarkdown = new CreateReleaseNotesHtml();
-			using(
-				var filesForTest = new TwoTempFilesForTest(Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.md"),
-					Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.htm")))
+			var sut = new CreateReleaseNotesHtml();
+			using (var filesForTest = new TwoTempFilesForTest(GetRandomFileEndingWith(".Test.md"),
+				      GetRandomFileEndingWith(".Test.htm")))
 			{
 				File.WriteAllLines(filesForTest.FirstFile,
 					new[]
 					{"## 2.3.9", "* with some random content", "* does some things", "## 2.3.7", "* more", "## 2.2.2", "* things"});
-				testMarkdown.ChangelogFile = filesForTest.FirstFile;
-				testMarkdown.HtmlFile = filesForTest.SecondFile;
-				Assert.That(testMarkdown.Execute(), Is.True);
+				sut.ChangelogFile = filesForTest.FirstFile;
+				sut.HtmlFile = filesForTest.SecondFile;
+				Assert.That(sut.Execute(), Is.True);
 			}
 		}
 
 		[Test]
-		public void RemovesKACHead()
+		public void RemovesKeepAChangelogHead()
 		{
-			var testMarkdown = new CreateReleaseNotesHtml();
-			using(
-				var filesForTest = new TwoTempFilesForTest(Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.md"),
-					Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.htm")))
+			var sut = new CreateReleaseNotesHtml();
+			using (var filesForTest = new TwoTempFilesForTest(GetRandomFileEndingWith(".Test.md"),
+					GetRandomFileEndingWith(".Test.htm")))
 			{
 				string changelogContent =
 @"# Change Log
 
-All notable changes to this project will be documented in this file.
+All notable changes to this project™ will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
@@ -78,8 +91,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - All bugs.";
 
 				string expectedHtml =
-@"<html><head></head><body><div class='releasenotes'>
-<h2>[2.3.4] - 2020-12-09</h2>
+$"<html><head><meta charset=\"UTF-8\"/></head><body><div {ReleaseNotesClassAttribute}>" +
+Environment.NewLine +
+@"<h2>[2.3.4] - 2020-12-09</h2>
 <h3>Changed</h3>
 <ul>
 <li>This to that.</li>
@@ -96,87 +110,110 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 </div></body></html>";
 
 				File.WriteAllText(filesForTest.FirstFile, changelogContent);
-				testMarkdown.ChangelogFile = filesForTest.FirstFile;
-				testMarkdown.HtmlFile = filesForTest.SecondFile;
+				sut.ChangelogFile = filesForTest.FirstFile;
+				sut.HtmlFile = filesForTest.SecondFile;
 				// SUT
-				Assert.That(testMarkdown.Execute(), Is.True);
+				Assert.That(sut.Execute(), Is.True);
 				string actualHtml = File.ReadAllText(filesForTest.SecondFile);
 				Assert.That(actualHtml, Is.EqualTo(expectedHtml));
 			}
 		}
 
-		[Test]
-		public void HtmlWithNoReleaseNotesElementIsCompletelyReplaced()
+		[TestCase(null)]
+		[TestCase("UTF-8")]
+		[TestCase("ISO-8859-1")]
+		public void HtmlWithNoReleaseNotesElement_IsCompletelyReplaced(string existingCharset)
 		{
-			var testMarkdown = new CreateReleaseNotesHtml();
-			using(
-				var filesForTest = new TwoTempFilesForTest(Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.md"),
-					Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.htm")))
+			var sut = new CreateReleaseNotesHtml();
+			using (var filesForTest = new TwoTempFilesForTest(GetRandomFileEndingWith(".Test.md"),
+					GetRandomFileEndingWith(".Test.htm")))
 			{
-				var ChangelogFile = filesForTest.FirstFile;
+				var changelogFile = filesForTest.FirstFile;
 				var htmlFile = filesForTest.SecondFile;
-				File.WriteAllLines(ChangelogFile,
-					new[]
-					{"## 2.3.9", "* with some random content", "* does some things", "## 2.3.7", "* more", "## 2.2.2", "* things"});
-				File.WriteAllLines(htmlFile,
-					new[] {"<html>", "<body>", "<div class='notmarkdown'/>", "</body>", "</html>"});
-				testMarkdown.ChangelogFile = ChangelogFile;
-				testMarkdown.HtmlFile = htmlFile;
-				Assert.That(testMarkdown.Execute(), Is.True);
-				AssertThatXmlIn.File(htmlFile).HasNoMatchForXpath("//div[@notmarkdown]");
+				File.WriteAllLines(changelogFile, new[]
+					{
+						"## 2.3.9", "* with some random content", "* does some things", "## 2.3.7",
+						"* more", "## 2.2.2", "* things"
+					});
+				var htmlLines = new List<string>(new[]
+					{ "<html>", "<body>", NotReleaseNotesDiv, "</body>", "</html>" });
+				if (existingCharset != null)
+				{
+					htmlLines.Insert(1, "<head>");
+					htmlLines.Insert(2, $"<meta charset = \"{existingCharset}\"/>");
+					htmlLines.Insert(3, "</head>");
+				}
+
+				File.WriteAllLines(htmlFile, htmlLines);
+				sut.ChangelogFile = changelogFile;
+				sut.HtmlFile = htmlFile;
+				Assert.That(sut.Execute(), Is.True);
+				AssertThatXmlIn.File(htmlFile).HasNoMatchForXpath(NotReleaseNotesDivXpath);
+				var expectedCharset = "UTF-8";
+				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath($"/html/head/meta[@charset='{expectedCharset}']", 1);
 			}
 		}
 
 		[Test]
-		public void HtmlWithReleaseNotesElementHasOnlyReleaseNoteElementChanged()
+		public void HtmlWithReleaseNotesElement_HasOnlyReleaseNoteElementChanged()
 		{
-			var testMarkdown = new CreateReleaseNotesHtml();
-			using(
-				var filesForTest = new TwoTempFilesForTest(Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.md"),
-					Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.htm")))
+			var sut = new CreateReleaseNotesHtml();
+			using (var filesForTest = new TwoTempFilesForTest(GetRandomFileEndingWith(".Test.md"),
+					GetRandomFileEndingWith(".Test.htm")))
 			{
-				var ChangelogFile = filesForTest.FirstFile;
+				var changelogFile = filesForTest.FirstFile;
 				var htmlFile = filesForTest.SecondFile;
-				File.WriteAllLines(ChangelogFile,
-					new[]
-					{"## 2.3.9", "* with some random content", "* does some things", "## 2.3.7", "* more", "## 2.2.2", "* things"});
-				File.WriteAllLines(htmlFile,
-					new[] {"<html>", "<body>", "<div class='notmarkdown'/>", "<div class='releasenotes'/>", "</body>", "</html>"});
-				testMarkdown.ChangelogFile = ChangelogFile;
-				testMarkdown.HtmlFile = htmlFile;
-				Assert.That(testMarkdown.Execute(), Is.True);
-				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath("//*[@class='notmarkdown']", 1);
-				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath("//*[@class='releasenotes']", 1);
-				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath("//*[@class='releasenotes']//*[text()[contains(., 'does some things')]]", 1);
+				File.WriteAllLines(changelogFile, new[]
+					{
+						"## 2.3.9", "* with some random content", "* does some things", "## 2.3.7",
+						"* more", "## 2.2.2", "* things"
+					});
+				File.WriteAllLines(htmlFile, new[]
+				{
+					"<html>", "<body>", NotReleaseNotesDiv,
+					$"<div {ReleaseNotesClassAttribute}/>", "</body>", "</html>"
+				});
+				sut.ChangelogFile = changelogFile;
+				sut.HtmlFile = htmlFile;
+				Assert.That(sut.Execute(), Is.True);
+				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath(
+					NotReleaseNotesDivXpath, 1);
+				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath(
+					$"//*[@{ReleaseNotesClassAttribute}]", 1);
+				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath(
+					$"//*[@{ReleaseNotesClassAttribute}]//*[text()[contains(., 'does some things')]]", 1);
 			}
 		}
 
 		[Test]
-		public void HtmlWithReleaseNotesElementWithContentsIsChanged()
+		public void HtmlWithReleaseNotesElementWithContents_IsChanged()
 		{
-			var testMarkdown = new CreateReleaseNotesHtml();
-			using(
-				var filesForTest = new TwoTempFilesForTest(Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.md"),
-					Path.Combine(Path.GetTempPath(), Path.GetRandomFileName()+".Test.htm")))
+			var sut = new CreateReleaseNotesHtml();
+			using (var filesForTest = new TwoTempFilesForTest(GetRandomFileEndingWith(".Test.md"),
+					GetRandomFileEndingWith(".Test.htm")))
 			{
-				var ChangelogFile = filesForTest.FirstFile;
+				var changelogFile = filesForTest.FirstFile;
 				var htmlFile = filesForTest.SecondFile;
-				File.WriteAllLines(ChangelogFile,
-					new[]
-					{"## 2.3.9", "* with some random content", "* does some things", "## 2.3.7", "* more", "## 2.2.2", "* things"});
-				File.WriteAllLines(htmlFile,
-					new[]
+				File.WriteAllLines(changelogFile, new[]
+					{
+						"## 2.3.9", "* with some random content", "* does some things", "## 2.3.7",
+						"* more", "## 2.2.2", "* things"
+					});
+				File.WriteAllLines(htmlFile, new[]
 					{
-						"<html>", "<body>", "<div class='releasenotes'>", "<span class='note'/>", "</div>",
-						"</body>", "</html>"
+						"<html>", "<head>", "<meta charset='UTF-8'/>", "</head>", "<body>",
+						$"<div {ReleaseNotesClassAttribute}>",
+						"<span class='note'/>", "</div>", "</body>", "</html>"
 					});
-				testMarkdown.ChangelogFile = ChangelogFile;
-				testMarkdown.HtmlFile = htmlFile;
-				Assert.That(testMarkdown.Execute(), Is.True);
+				sut.ChangelogFile = changelogFile;
+				sut.HtmlFile = htmlFile;
+				Assert.That(sut.Execute(), Is.True);
+				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath(
+					"/html/head/meta[@charset='UTF-8']", 1);
 				AssertThatXmlIn.File(htmlFile).HasNoMatchForXpath("//span[@class='note']");
-				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath("//*[@class='releasenotes']", 1);
+				AssertThatXmlIn.File(htmlFile).HasSpecifiedNumberOfMatchesForXpath(
+					$"//*[@{ReleaseNotesClassAttribute}]", 1);
 			}
 		}
-
 	}
 }
diff --git a/SIL.ReleaseTasks/CreateReleaseNotesHtml.cs b/SIL.ReleaseTasks/CreateReleaseNotesHtml.cs
index 32cded4a..910bbf41 100644
--- a/SIL.ReleaseTasks/CreateReleaseNotesHtml.cs
+++ b/SIL.ReleaseTasks/CreateReleaseNotesHtml.cs
@@ -1,4 +1,4 @@
-// Copyright (c) 2018 SIL Global
+// Copyright (c) 2018-2025 SIL Global
 // This software is licensed under the MIT License (http://opensource.org/licenses/MIT)
 
 using System;
@@ -15,13 +15,17 @@ namespace SIL.ReleaseTasks
 	/// <inheritdoc />
 	/// <summary>
 	/// Given a markdown-style changelog file, this class will generate a release notes HTML file.
-	/// If the HTML file already exists, the task will look for a section with `class="releasenotes"`
-	/// and replace it with the current release notes.
-	/// The developer-oriented and [Unreleased] beginning will be removed from a Keep a Changelog style changelog.
+	/// If the HTML file already exists, the task will look for a section with
+	/// `class="<see cref="kReleaseNotesClassName"/>>"` and replace it with the current release
+	/// notes.
+	/// The developer-oriented and [Unreleased] beginning will be removed from a Keep a Changelog
+	/// style changelog.
 	/// </summary>
 	[SuppressMessage("ReSharper", "MemberCanBePrivate.Global")]
 	public class CreateReleaseNotesHtml : Task
 	{
+		public const string kReleaseNotesClassName = "releasenotes";
+
 		[Required]
 		public string HtmlFile { get; set; }
 
@@ -39,27 +43,28 @@ public override bool Execute()
 			try
 			{
 				string inputMarkdown = File.ReadAllText(ChangelogFile);
-				CreateReleaseNotesHtml.RemoveKeepAChangelogHeadIfPresent(ref inputMarkdown);
-				// MarkdownDeep appears to use \n for newlines. Rather than mix those with platform line-endings, just
-				// convert them to platform line-endings if needed.
+				RemoveKeepAChangelogHeadIfPresent(ref inputMarkdown);
+				// MarkDig appears to use \n for newlines. Rather than mix those with platform
+				// line-endings, just convert them to platform line-endings if needed.
 				var markdownHtml = Markdown.ToHtml(inputMarkdown).Replace("\n", Environment.NewLine);
-				if(File.Exists(HtmlFile))
+				XElement releaseNotesElement = null;
+				XDocument htmlDoc = null;
+				if (File.Exists(HtmlFile))
+				{
+					htmlDoc = XDocument.Load(HtmlFile);
+					var releaseNotesElementXpath = $"//*[@class='{kReleaseNotesClassName}']";
+					releaseNotesElement = htmlDoc.XPathSelectElement(releaseNotesElementXpath);
+				}
+				if (releaseNotesElement == null)
+					WriteBasicHtmlFromMarkdown(markdownHtml);
+				else
 				{
-					var htmlDoc = XDocument.Load(HtmlFile);
-					var releaseNotesElement = htmlDoc.XPathSelectElement("//*[@class='releasenotes']");
-					if (releaseNotesElement == null)
-						return true;
-
 					releaseNotesElement.RemoveNodes();
 					var mdDocument = XDocument.Parse($"<div>{markdownHtml}</div>");
 					// ReSharper disable once PossibleNullReferenceException - Will either throw or work
 					releaseNotesElement.Add(mdDocument.Root.Elements());
 					htmlDoc.Save(HtmlFile);
 				}
-				else
-				{
-					WriteBasicHtmlFromMarkdown(markdownHtml);
-				}
 				return true;
 			}
 			catch(Exception e)
@@ -71,7 +76,9 @@ public override bool Execute()
 
 		private void WriteBasicHtmlFromMarkdown(string markdownHtml)
 		{
-			File.WriteAllText(HtmlFile, $"<html><head></head><body><div class='releasenotes'>{Environment.NewLine}{markdownHtml}</div></body></html>");
+			File.WriteAllText(HtmlFile, "<html><head><meta charset=\"UTF-8\"/></head><body>" +
+				$"<div class='{kReleaseNotesClassName}'>" +
+				$"{Environment.NewLine}{markdownHtml}</div></body></html>");
 		}
 
 		/// <summary>
@@ -81,9 +88,7 @@ private void WriteBasicHtmlFromMarkdown(string markdownHtml)
 		public static bool RemoveKeepAChangelogHeadIfPresent(ref string md)
 		{
 			if (!md.Contains("[Unreleased]"))
-			{
 				return false;
-			}
 			string unreleasedHeader = $"## [Unreleased]{Environment.NewLine}{Environment.NewLine}";
 			int unreleasedHeaderLocation = md.IndexOf(unreleasedHeader);
 			md = md.Substring(unreleasedHeaderLocation + unreleasedHeader.Length);