diff --git a/.appveyor.yml b/.appveyor.yml
deleted file mode 100644
index e4a0461e..00000000
--- a/.appveyor.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-version: '{build}'
-branches:
-  only:
-  - master
-  - /^v\d+(?:\.\d+)?$/
-  - /[\b_]validate\b/
-skip_tags: true
-nuget:
-  disable_publish_on_pr: true
-image: Visual Studio 2017
-configuration: Release
-environment:
-  VisualStudioVersion: 15.0
-init:
-  git config --global core.autocrlf true
-build_script:
-- ps: Build\runbuild.ps1
-artifacts:
-- path: Working\NuGet\*.nupkg
-  name: NuGet Package
diff --git a/Build/build.ps1 b/Build/build.ps1
index 87d2bdad..5e55a268 100644
--- a/Build/build.ps1
+++ b/Build/build.ps1
@@ -14,7 +14,7 @@
   $workingName = if ($workingName) {$workingName} else {"Working"}
   $assemblyVersion = if ($assemblyVersion) {$assemblyVersion} else {$majorVersion + '.0.0'}
   $netCliChannel = "STS"
-  $netCliVersion = "8.0.300"
+  $netCliVersion = "9.0.300"
   $nugetUrl = "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe"
   $ensureNetCliSdk = $true
 
@@ -151,7 +151,7 @@ task Test -depends Build {
 
 function NetCliBuild()
 {
-  $projectPath = "$sourceDir\Newtonsoft.Json.sln"
+  $projectPath = "$sourceDir\Newtonsoft.Json.slnx"
   $libraryFrameworks = ($script:enabledBuilds | Select-Object @{Name="Framework";Expression={$_.Framework}} | select -expand Framework) -join ";"
   $testFrameworks = ($script:enabledBuilds | Select-Object @{Name="Resolved";Expression={if ($_.TestFramework -ne $null) { $_.TestFramework } else { $_.Framework }}} | select -expand Resolved) -join ";"
 
diff --git a/Src/Newtonsoft.Json.sln b/Src/Newtonsoft.Json.sln
deleted file mode 100644
index 43b77487..00000000
--- a/Src/Newtonsoft.Json.sln
+++ /dev/null
@@ -1,86 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.29123.89
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{B520C700-7D45-4D82-BFB5-218FA68CF5CF}"
-	ProjectSection(SolutionItems) = preProject
-		Directory.Build.props = Directory.Build.props
-		global.json = global.json
-		NuGet.Config = NuGet.Config
-	EndProjectSection
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Newtonsoft.Json", "Newtonsoft.Json\Newtonsoft.Json.csproj", "{A97A4CB3-51AD-4605-BA9F-D6861E582C85}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Newtonsoft.Json.Tests", "Newtonsoft.Json.Tests\Newtonsoft.Json.Tests.csproj", "{462EA9B9-8532-4330-9160-DF3450C70880}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Newtonsoft.Json.TestConsole", "Newtonsoft.Json.TestConsole\Newtonsoft.Json.TestConsole.csproj", "{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Newtonsoft.Json.FuzzTests", "Newtonsoft.Json.FuzzTests\Newtonsoft.Json.FuzzTests.csproj", "{00867C2B-409D-45B2-A78F-F291B6817F70}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Debug|x64 = Debug|x64
-		Debug|x86 = Debug|x86
-		Release|Any CPU = Release|Any CPU
-		Release|x64 = Release|x64
-		Release|x86 = Release|x86
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Debug|x64.Build.0 = Debug|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Debug|x86.Build.0 = Debug|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Release|Any CPU.Build.0 = Release|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Release|x64.ActiveCfg = Release|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Release|x64.Build.0 = Release|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Release|x86.ActiveCfg = Release|Any CPU
-		{A97A4CB3-51AD-4605-BA9F-D6861E582C85}.Release|x86.Build.0 = Release|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Debug|x64.Build.0 = Debug|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Debug|x86.Build.0 = Debug|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Release|Any CPU.Build.0 = Release|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Release|x64.ActiveCfg = Release|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Release|x64.Build.0 = Release|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Release|x86.ActiveCfg = Release|Any CPU
-		{462EA9B9-8532-4330-9160-DF3450C70880}.Release|x86.Build.0 = Release|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Debug|x64.Build.0 = Debug|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Debug|x86.Build.0 = Debug|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Release|x64.ActiveCfg = Release|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Release|x64.Build.0 = Release|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Release|x86.ActiveCfg = Release|Any CPU
-		{3CC9C2DF-CD0A-4096-BF46-B4AFDF0147D2}.Release|x86.Build.0 = Release|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Debug|x64.Build.0 = Debug|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Debug|x86.Build.0 = Debug|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Release|Any CPU.Build.0 = Release|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Release|x64.ActiveCfg = Release|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Release|x64.Build.0 = Release|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Release|x86.ActiveCfg = Release|Any CPU
-		{00867C2B-409D-45B2-A78F-F291B6817F70}.Release|x86.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-	GlobalSection(ExtensibilityGlobals) = postSolution
-		SolutionGuid = {225F391C-701E-49A2-8193-085EC2586689}
-	EndGlobalSection
-EndGlobal
diff --git a/Src/Newtonsoft.Json.sln.DotSettings b/Src/Newtonsoft.Json.sln.DotSettings
deleted file mode 100644
index 72cfc364..00000000
--- a/Src/Newtonsoft.Json.sln.DotSettings
+++ /dev/null
@@ -1,22 +0,0 @@
-<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
-	<s:Int64 x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_BLANK_LINES_IN_CODE/@EntryValue">1</s:Int64>
-	<s:Int64 x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_BLANK_LINES_IN_DECLARATIONS/@EntryValue">1</s:Int64>
-	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_ACCESSOR_ATTRIBUTE_ON_SAME_LINE_EX/@EntryValue">NEVER</s:String>
-	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_ACCESSORHOLDER_ATTRIBUTE_ON_SAME_LINE_EX/@EntryValue">NEVER</s:String>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_FIELD_ATTRIBUTE_ON_SAME_LINE/@EntryValue">False</s:Boolean>
-	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_FIELD_ATTRIBUTE_ON_SAME_LINE_EX/@EntryValue">NEVER</s:String>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_ACCESSOR_ATTRIBUTE_ON_SAME_LINE/@EntryValue">False</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_AFTER_TYPECAST_PARENTHESES/@EntryValue">False</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_AROUND_MULTIPLICATIVE_OP/@EntryValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_BEFORE_SIZEOF_PARENTHESES/@EntryValue">False</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_BEFORE_TYPEOF_PARENTHESES/@EntryValue">False</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_LINES/@EntryValue">False</s:Boolean>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpAttributeForSingleLineMethodUpgrade/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpKeepExistingMigration/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpPlaceEmbeddedOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpRenamePlacementToArrangementMigration/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EAddAccessorOwnerDeclarationBracesMigration/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002ECSharpPlaceAttributeOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateBlankLinesAroundFieldToBlankLinesAroundProperty/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateThisQualifierSettings/@EntryIndexedValue">True</s:Boolean>
-</wpf:ResourceDictionary>
\ No newline at end of file
diff --git a/Src/Newtonsoft.Json.slnx b/Src/Newtonsoft.Json.slnx
new file mode 100644
index 00000000..a03d026c
--- /dev/null
+++ b/Src/Newtonsoft.Json.slnx
@@ -0,0 +1,16 @@
+<Solution>
+  <Configurations>
+    <Platform Name="Any CPU" />
+    <Platform Name="x64" />
+    <Platform Name="x86" />
+  </Configurations>
+  <Folder Name="/Solution Items/">
+    <File Path="Directory.Build.props" />
+    <File Path="global.json" />
+    <File Path="NuGet.Config" />
+  </Folder>
+  <Project Path="Newtonsoft.Json.FuzzTests/Newtonsoft.Json.FuzzTests.csproj" />
+  <Project Path="Newtonsoft.Json.TestConsole/Newtonsoft.Json.TestConsole.csproj" />
+  <Project Path="Newtonsoft.Json.Tests/Newtonsoft.Json.Tests.csproj" />
+  <Project Path="Newtonsoft.Json/Newtonsoft.Json.csproj" />
+</Solution>
diff --git a/Src/global.json b/Src/global.json
index e972eb19..3be1c15a 100644
--- a/Src/global.json
+++ b/Src/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.300",
+    "version": "9.0.300",
     "rollForward": "latestFeature"
   }
 }
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 80277984..6934b34e 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -6,9 +6,14 @@ pool:
   vmImage: 'windows-2022'
 
 steps:
+- task: UseDotNet@2
+  inputs:
+    version: '9.0.x'
+
 - task: UseDotNet@2
   inputs:
     version: '8.0.x'
+    packageType: runtime
 
 - task: UseDotNet@2
   inputs:
@@ -17,7 +22,7 @@ steps:
 
 - task: UseDotNet@2
   inputs:
-    version: '2.1.x'
+    version: '5.0.x'
     packageType: runtime
 
 - task: UseDotNet@2
@@ -27,7 +32,7 @@ steps:
 
 - task: UseDotNet@2
   inputs:
-    version: '5.0.x'
+    version: '2.1.x'
     packageType: runtime
 
 - powershell: |