diff --git a/ExternalToolProjects/.build_from_cwd_debug.sh b/ExternalToolProjects/.build_net48_from_cwd_debug.sh
similarity index 65%
rename from ExternalToolProjects/.build_from_cwd_debug.sh
rename to ExternalToolProjects/.build_net48_from_cwd_debug.sh
index d9cec13428..2f0184cb55 100755
--- a/ExternalToolProjects/.build_from_cwd_debug.sh
+++ b/ExternalToolProjects/.build_net48_from_cwd_debug.sh
@@ -1,3 +1,3 @@
 #!/bin/sh
 name="$(basename "$PWD").dll"
-CscToolExe="$(which csc)" dotnet build -c Debug -m && cp -f "bin/Debug/$name" "../../output/ExternalTools/$name"
+CscToolExe="$(which csc)" dotnet build -c Debug -m && cp -f "bin/Debug/net48/$name" "../../output/ExternalTools/$name"
diff --git a/ExternalToolProjects/.build_from_cwd_release.sh b/ExternalToolProjects/.build_net48_from_cwd_release.sh
similarity index 63%
rename from ExternalToolProjects/.build_from_cwd_release.sh
rename to ExternalToolProjects/.build_net48_from_cwd_release.sh
index 3315f6f4e6..40d7ba70db 100755
--- a/ExternalToolProjects/.build_from_cwd_release.sh
+++ b/ExternalToolProjects/.build_net48_from_cwd_release.sh
@@ -1,3 +1,3 @@
 #!/bin/sh
 name="$(basename "$PWD").dll"
-CscToolExe="$(which csc)" dotnet build -c Release -m && cp -f "bin/Release/$name" "../../output/ExternalTools/$name"
+CscToolExe="$(which csc)" dotnet build -c Release -m && cp -f "bin/Release/net48/$name" "../../output/ExternalTools/$name"
diff --git a/ExternalToolProjects/Common.props b/ExternalToolProjects/Common.props
new file mode 100644
index 0000000000..76d80bbf9a
--- /dev/null
+++ b/ExternalToolProjects/Common.props
@@ -0,0 +1,29 @@
+<Project>
+	<PropertyGroup>
+		<CodeAnalysisRuleSet>$(ProjectDir)../../Common.ruleset</CodeAnalysisRuleSet>
+		<ErrorReport>prompt</ErrorReport>
+		<GenerateAssemblyInfo>false</GenerateAssemblyInfo>
+		<LangVersion>8.0</LangVersion>
+		<Nullable>enable</Nullable>
+		<OutputPath>$(ProjectDir)bin/$(Configuration)</OutputPath>
+		<PlatformTarget>AnyCPU</PlatformTarget>
+		<RunAnalyzersDuringBuild Condition=" '$(MachineRunAnalyzersDuringBuild)' == '' ">false</RunAnalyzersDuringBuild>
+		<RunCodeAnalysis>false</RunCodeAnalysis>
+	</PropertyGroup>
+	<PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
+		<DebugSymbols>true</DebugSymbols>
+		<DebugType>full</DebugType>
+		<DefineConstants>DEBUG;TRACE</DefineConstants>
+		<Optimize>false</Optimize>
+	</PropertyGroup>
+	<PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+		<DebugSymbols>false</DebugSymbols>
+		<DebugType>pdbonly</DebugType>
+		<DefineConstants>TRACE</DefineConstants>
+		<Optimize>true</Optimize>
+	</PropertyGroup>
+	<ItemGroup>
+		<AdditionalFiles Include="$(ProjectDir)../../.stylecop.json" />
+		<Compile Remove="*.sh" />
+	</ItemGroup>
+</Project>
diff --git a/ExternalToolProjects/HelloWorld/CustomMainForm.cs b/ExternalToolProjects/HelloWorld/CustomMainForm.cs
index d112a3da4b..14a80644b6 100644
--- a/ExternalToolProjects/HelloWorld/CustomMainForm.cs
+++ b/ExternalToolProjects/HelloWorld/CustomMainForm.cs
@@ -5,65 +5,115 @@ using System.IO;
 using BizHawk.Client.ApiHawk;
 using BizHawk.Client.Common;
 using BizHawk.Emulation.Common;
-using BizHawk.Client.ApiHawk.Classes.Events;
+
+using DisplayType = BizHawk.Client.Common.DisplayType;
 
 namespace BizHawk.Client.EmuHawk
 {
-	/// <summary>
-	/// Here your first form
-	/// /!\ it MUST be called CustomMainForm and implements IExternalToolForm
-	/// Take also care of the namespace
-	/// </summary>
+	/// <remarks><see cref="IExternalToolForm">ExternalToolForms</see> must be a class named <c>CustomMainForm</c> in namespace <c>BizHawk.Client.EmuHawk</c>.</remarks>
 	public partial class CustomMainForm : Form, IExternalToolForm
 	{
-		#region Fields
-
-		/*
-		The following stuff will be automatically filled
-		by BizHawk runtime
-		*/
+		/// <remarks><see cref="RequiredServiceAttribute">RequiredServices</see> are populated by EmuHawk at runtime.</remarks>
 		[RequiredService]
-		internal IMemoryDomains _memoryDomains { get; set; }
+		private IEmulator? _emu { get; set; }
+
 		[RequiredService]
-		private IEmulator _emu { get; set; }
+		private IMemoryDomains? _memoryDomains { get; set; }
 
-		/*private members for our needed*/
-		private WatchList _watches;
+		private WatchList? _watches;
 
-		#endregion
-
-		#region cTor(s)
+		private WatchList Watches
+		{
+			get
+			{
+				WatchList CreateWatches()
+				{
+					var w = new WatchList(_memoryDomains, _emu?.SystemId ?? string.Empty);
+					w.AddRange(new[] {
+						Watch.GenerateWatch(_memoryDomains?.MainMemory, 0x40, WatchSize.Byte, DisplayType.Hex, true),
+						Watch.GenerateWatch(_memoryDomains?.MainMemory, 0x50, WatchSize.Word, DisplayType.Unsigned, true),
+						Watch.GenerateWatch(_memoryDomains?.MainMemory, 0x60, WatchSize.DWord, DisplayType.Hex, true)
+					});
+					return w;
+				}
+				_watches ??= CreateWatches();
+				return _watches;
+			}
+		}
 
 		public CustomMainForm()
 		{
 			InitializeComponent();
-			label_GameHash.Click += Label_GameHash_Click;
+			label_GameHash.Click += label_GameHash_Click;
 
-			ClientApi.BeforeQuickSave += ClientApi_BeforeQuickSave;
-			ClientApi.BeforeQuickLoad += ClientApi_BeforeQuickLoad;
+			ClientApi.BeforeQuickSave += (sender, e) =>
+			{
+				if (e.Slot != 0) return; // only take effect on slot 0
+				var basePath = Path.Combine(PathManager.GetSaveStatePath(Global.Game), "Test");
+				if (!Directory.Exists(basePath)) Directory.CreateDirectory(basePath);
+				ClientApi.SaveState(Path.Combine(basePath, e.Name));
+				e.Handled = true;
+			};
+			ClientApi.BeforeQuickLoad += (sender, e) =>
+			{
+				if (e.Slot != 0) return; // only take effect on slot 0
+				var basePath = Path.Combine(PathManager.GetSaveStatePath(Global.Game), "Test");
+				ClientApi.LoadState(Path.Combine(basePath, e.Name));
+				e.Handled = true;
+			};
 		}
 
-		#endregion
+		/// <remarks>We want <see cref="UpdateValues"/> to be called before rendering.</remarks>
+		public bool UpdateBefore => true;
 
-		#region Methods
+		public bool AskSaveChanges() => true;
 
-		private void button1_Click(object sender, EventArgs e)
+		/// <remarks>This is called instead of the usual <see cref="UpdateValues"/> when EmuHawk is turboing.</remarks>
+		public void FastUpdate() {}
+
+		public void NewUpdate(ToolFormUpdateType type) {}
+
+		/// <remarks>This is called once when the form is opened, and every time a new movie session starts.</remarks>
+		public void Restart()
 		{
-			ClientApi.DoFrameAdvance();
+#if false
+			ClientApi.SetExtraPadding(50, 50);
+#endif
+
+			if (Global.Game.Name != "Null")
+			{
+				Watches.RefreshDomains(_memoryDomains);
+				label_Game.Text = $"You're playing {Global.Game.Name}";
+				label_GameHash.Text = $"Hash: {Global.Game.Hash}";
+			}
+			else
+			{
+				label_Game.Text = "You're playing... nothing";
+				label_GameHash.Text = string.Empty;
+			}
 		}
 
-		private void button2_Click(object sender, EventArgs e)
+		/// <remarks>Called just before every video frame.</remarks>
+		public void UpdateValues()
 		{
-			ClientApi.GetInput(1);
+			if (Global.Game.Name == "Null" || Watches.Count < 3) return;
+			Watches.UpdateValues();
+			label_Watch1.Text = $"First watch ({Watches[0].AddressString}) current value: {Watches[0].ValueString}";
+			label_Watch2.Text = $"Second watch ({Watches[1].AddressString}) current value: {Watches[1].ValueString}";
+			label_Watch3.Text = $"Third watch ({Watches[2].AddressString}) current value: {Watches[2].ValueString}";
 		}
 
+		private void button1_Click(object sender, EventArgs e) => ClientApi.DoFrameAdvance();
+
+		private void button2_Click(object sender, EventArgs e) => ClientApi.GetInput(1);
+
 		private void button3_Click(object sender, EventArgs e)
 		{
-			for (int i = 0; i < 600; i++)
+			for (var i = 0; i < 600; i++)
 			{
 				if (i % 60 == 0)
 				{
-					Joypad j1 = ClientApi.GetInput(1);
+					var j1 = ClientApi.GetInput(1);
 					j1.AddInput(JoypadButton.A);
 					ClientApi.SetInput(1, j1);
 
@@ -75,154 +125,29 @@ namespace BizHawk.Client.EmuHawk
 				}
 				ClientApi.DoFrameAdvance();
 			}
-			Joypad j = ClientApi.GetInput(1);
+			var j = ClientApi.GetInput(1);
 			j.ClearInputs();
 			ClientApi.SetInput(1, j);
 		}
 
-		private void Label_GameHash_Click(object sender, EventArgs e)
-		{
-			Clipboard.SetText(Global.Game.Hash);
-		}
+		private void label_GameHash_Click(object sender, EventArgs e) => Clipboard.SetText(Global.Game.Hash);
 
 		private void loadstate_Click(object sender, EventArgs e)
 		{
-			if (savestateName.Text.Trim() != string.Empty)
+			if (string.IsNullOrWhiteSpace(savestateName.Text)) return;
+			ClientApi.LoadState(savestateName.Text);
+#if false
+			static void Test(BinaryReader r)
 			{
-				ClientApi.LoadState(savestateName.Text);
-				//BinaryStateLoader.LoadAndDetect(savestateName.Text + ".State").GetLump(BinaryStateLump.Framebuffer, false, Test);
+				var b = new System.Drawing.Bitmap(r.BaseStream);
 			}
+			BinaryStateLoader.LoadAndDetect($"{savestateName.Text}.State").GetLump(BinaryStateLump.Framebuffer, false, Test);
+#endif
 		}
 
-		/*private void Test(BinaryReader r)
-		{
-			System.Drawing.Bitmap b = new System.Drawing.Bitmap(r.BaseStream);
-		}*/
-
 		private void saveState_Click(object sender, EventArgs e)
 		{
-			if (savestateName.Text.Trim() != string.Empty)
-			{
-				ClientApi.SaveState(savestateName.Text);
-			}
+			if (!string.IsNullOrWhiteSpace(savestateName.Text)) ClientApi.SaveState(savestateName.Text);
 		}
-
-		//We will override F10 quicksave behavior
-		private void ClientApi_BeforeQuickSave(object sender, BeforeQuickSaveEventArgs e)
-		{
-			if(e.Slot == 0)
-			{
-				string basePath = Path.Combine(PathManager.GetSaveStatePath(Global.Game), "Test");
-				if (!Directory.Exists(basePath))
-				{
-					Directory.CreateDirectory(basePath);
-				}
-				ClientApi.SaveState(Path.Combine(basePath, e.Name));
-				e.Handled = true;
-			}
-		}
-
-		//We will override F10 quickload behavior
-		private void ClientApi_BeforeQuickLoad(object sender, BeforeQuickLoadEventArgs e)
-		{
-			if (e.Slot == 0)
-			{
-				string basePath = Path.Combine(PathManager.GetSaveStatePath(Global.Game), "Test");
-				ClientApi.LoadState(Path.Combine(basePath, e.Name));
-				e.Handled = true;
-			}
-		}
-
-		#endregion
-
-		#region BizHawk Required methods
-
-		/// <summary>
-		/// Return true if you want the <see cref="UpdateValues"/> method
-		/// to be called before rendering
-		/// </summary>
-		public bool UpdateBefore
-		{
-			get
-			{
-				return true;
-			}
-		}
-
-		public bool AskSaveChanges()
-		{
-			return true;
-		}
-
-		/// <summary>
-		/// This method is called instead of regular <see cref="UpdateValues"/>
-		/// when emulator is runnig in turbo mode
-		/// </summary>
-		public void FastUpdate()
-		{ }
-
-		public void NewUpdate(ToolFormUpdateType type) {}
-
-		/// <summary>
-		/// Restart is called the first time you call the form
-		/// but also when you start playing a movie
-		/// </summary>
-		public void Restart()
-		{
-			//set a client padding
-//			ClientApi.SetExtraPadding(50, 50);
-
-			if (Global.Game.Name != "Null")
-			{
-				//first initialization of WatchList
-				if (_watches == null)
-				{
-					_watches = new WatchList(_memoryDomains, _emu.SystemId ?? string.Empty);
-
-					//Create some watch
-					Watch myFirstWatch = Watch.GenerateWatch(_memoryDomains.MainMemory, 0x40, WatchSize.Byte, BizHawk.Client.Common.DisplayType.Hex, true);
-					Watch mySecondWatch = Watch.GenerateWatch(_memoryDomains.MainMemory, 0x50, WatchSize.Word, BizHawk.Client.Common.DisplayType.Unsigned, true);
-					Watch myThirdWatch = Watch.GenerateWatch(_memoryDomains.MainMemory, 0x60, WatchSize.DWord, BizHawk.Client.Common.DisplayType.Hex, true);
-
-					//add them into the list
-					_watches.Add(myFirstWatch);
-					_watches.Add(mySecondWatch);
-					_watches.Add(myThirdWatch);
-
-					label_Game.Text = string.Format("You're playing {0}", Global.Game.Name);
-					label_GameHash.Text = string.Format("Hash: {0}", Global.Game.Hash);
-				}
-				//refresh it
-				else
-				{
-					_watches.RefreshDomains(_memoryDomains);
-					label_Game.Text = string.Format("You're playing {0}", Global.Game.Name);
-					label_GameHash.Text = string.Format("Hash: {0}", Global.Game.Hash);
-				}
-			}
-			else
-			{
-				label_Game.Text = string.Format("You aren't playing to anything");
-				label_GameHash.Text = string.Empty;
-			}
-		}
-
-		/// <summary>
-		/// This method is called when a frame is rendered
-		/// You can comapre it the lua equivalent emu.frameadvance()
-		/// </summary>
-		public void UpdateValues()
-		{
-			if (Global.Game.Name != "Null")
-			{
-				//we update our watches
-				_watches.UpdateValues();
-				label_Watch1.Text = string.Format("First watch ({0}) current value: {1}", _watches[0].AddressString, _watches[0].ValueString);
-				label_Watch2.Text = string.Format("Second watch ({0}) current value: {1}", _watches[1].AddressString, _watches[1].ValueString);
-				label_Watch3.Text = string.Format("Third watch ({0}) current value: {1}", _watches[2].AddressString, _watches[2].ValueString);
-			}
-		}
-
-		#endregion BizHawk Required methods
 	}
 }
diff --git a/ExternalToolProjects/HelloWorld/CustomMainForm.resx b/ExternalToolProjects/HelloWorld/CustomMainForm.resx
deleted file mode 100644
index 29dcb1b3a3..0000000000
--- a/ExternalToolProjects/HelloWorld/CustomMainForm.resx
+++ /dev/null
@@ -1,120 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<root>
-  <!-- 
-    Microsoft ResX Schema 
-    
-    Version 2.0
-    
-    The primary goals of this format is to allow a simple XML format 
-    that is mostly human readable. The generation and parsing of the 
-    various data types are done through the TypeConverter classes 
-    associated with the data types.
-    
-    Example:
-    
-    ... ado.net/XML headers & schema ...
-    <resheader name="resmimetype">text/microsoft-resx</resheader>
-    <resheader name="version">2.0</resheader>
-    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
-    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
-    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
-    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
-    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
-        <value>[base64 mime encoded serialized .NET Framework object]</value>
-    </data>
-    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
-        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
-        <comment>This is a comment</comment>
-    </data>
-                
-    There are any number of "resheader" rows that contain simple 
-    name/value pairs.
-    
-    Each data row contains a name, and value. The row also contains a 
-    type or mimetype. Type corresponds to a .NET class that support 
-    text/value conversion through the TypeConverter architecture. 
-    Classes that don't support this are serialized and stored with the 
-    mimetype set.
-    
-    The mimetype is used for serialized objects, and tells the 
-    ResXResourceReader how to depersist the object. This is currently not 
-    extensible. For a given mimetype the value must be set accordingly:
-    
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
-    that the ResXResourceWriter will generate, however the reader can 
-    read any of the formats listed below.
-    
-    mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
-            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
-            : and then encoded with base64 encoding.
-    
-    mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
-            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
-            : and then encoded with base64 encoding.
-
-    mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
-            : using a System.ComponentModel.TypeConverter
-            : and then encoded with base64 encoding.
-    -->
-  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
-    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
-    <xsd:element name="root" msdata:IsDataSet="true">
-      <xsd:complexType>
-        <xsd:choice maxOccurs="unbounded">
-          <xsd:element name="metadata">
-            <xsd:complexType>
-              <xsd:sequence>
-                <xsd:element name="value" type="xsd:string" minOccurs="0" />
-              </xsd:sequence>
-              <xsd:attribute name="name" use="required" type="xsd:string" />
-              <xsd:attribute name="type" type="xsd:string" />
-              <xsd:attribute name="mimetype" type="xsd:string" />
-              <xsd:attribute ref="xml:space" />
-            </xsd:complexType>
-          </xsd:element>
-          <xsd:element name="assembly">
-            <xsd:complexType>
-              <xsd:attribute name="alias" type="xsd:string" />
-              <xsd:attribute name="name" type="xsd:string" />
-            </xsd:complexType>
-          </xsd:element>
-          <xsd:element name="data">
-            <xsd:complexType>
-              <xsd:sequence>
-                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
-                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
-              </xsd:sequence>
-              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
-              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
-              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
-              <xsd:attribute ref="xml:space" />
-            </xsd:complexType>
-          </xsd:element>
-          <xsd:element name="resheader">
-            <xsd:complexType>
-              <xsd:sequence>
-                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
-              </xsd:sequence>
-              <xsd:attribute name="name" type="xsd:string" use="required" />
-            </xsd:complexType>
-          </xsd:element>
-        </xsd:choice>
-      </xsd:complexType>
-    </xsd:element>
-  </xsd:schema>
-  <resheader name="resmimetype">
-    <value>text/microsoft-resx</value>
-  </resheader>
-  <resheader name="version">
-    <value>2.0</value>
-  </resheader>
-  <resheader name="reader">
-    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
-  </resheader>
-  <resheader name="writer">
-    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
-  </resheader>
-</root>
\ No newline at end of file
diff --git a/ExternalToolProjects/HelloWorld/HelloWorld.csproj b/ExternalToolProjects/HelloWorld/HelloWorld.csproj
index f79340d31e..7827027f2b 100644
--- a/ExternalToolProjects/HelloWorld/HelloWorld.csproj
+++ b/ExternalToolProjects/HelloWorld/HelloWorld.csproj
@@ -1,80 +1,11 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="../../DotNetBuild.Common.targets" Condition=" '$(OS)' != 'Windows_NT' " />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <ProjectGuid>{288D598F-1019-4EA2-802D-14D3CC73EE90}</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <AppDesignerFolder>Properties</AppDesignerFolder>
-    <RootNamespace>HelloWorld</RootNamespace>
-    <AssemblyName>HelloWorld</AssemblyName>
-    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
-    <FileAlignment>512</FileAlignment>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <PlatformTarget>x64</PlatformTarget>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <PlatformTarget>x64</PlatformTarget>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference
-      HintPath="../../output/BizHawk.Client.ApiHawk.dll"
-      Include="BizHawk.Client.ApiHawk" />
-    <Reference
-      HintPath="../../output/BizHawk.Client.Common.dll"
-      Include="BizHawk.Client.Common" />
-    <Reference
-      HintPath="../../output/BizHawk.Emulation.Common.dll"
-      Include="BizHawk.Emulation.Common" />
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Drawing" />
-    <Reference Include="System.Windows.Forms" />
-    <Reference Include="System.Xml.Linq" />
-    <Reference Include="System.Data.DataSetExtensions" />
-    <Reference Include="Microsoft.CSharp" />
-    <Reference Include="System.Data" />
-    <Reference Include="System.Xml" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="CustomMainForm.cs">
-      <SubType>Form</SubType>
-    </Compile>
-    <Compile Include="CustomMainForm.Designer.cs">
-      <DependentUpon>CustomMainForm.cs</DependentUpon>
-    </Compile>
-    <Compile Include="Properties\AssemblyInfo.cs" />
-  </ItemGroup>
-  <ItemGroup>
-    <EmbeddedResource Include="CustomMainForm.resx">
-      <DependentUpon>CustomMainForm.cs</DependentUpon>
-    </EmbeddedResource>
-  </ItemGroup>
-  <ItemGroup>
-    <EmbeddedResource Include="icon_Hello.ico" />
-  </ItemGroup>
-  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
+<Project Sdk="Microsoft.NET.Sdk">
+	<Import Project="$(ProjectDir)../Common.props" />
+	<Import Project="$(ProjectDir)../NET48ExternalToolForm.props" />
+	<ItemGroup>
+		<EmbeddedResource Include="icon_Hello.ico" />
+	</ItemGroup>
+	<ItemGroup>
+		<Compile Update="CustomMainForm.cs" SubType="Form" />
+		<Compile Update="CustomMainForm.Designer.cs" DependentUpon="CustomMainForm.cs" />
+	</ItemGroup>
+</Project>
diff --git a/ExternalToolProjects/HelloWorld/build_debug.sh b/ExternalToolProjects/HelloWorld/build_debug.sh
index 43e0170d2e..c4d41e9cbf 120000
--- a/ExternalToolProjects/HelloWorld/build_debug.sh
+++ b/ExternalToolProjects/HelloWorld/build_debug.sh
@@ -1 +1 @@
-../.build_from_cwd_debug.sh
\ No newline at end of file
+../.build_net48_from_cwd_debug.sh
\ No newline at end of file
diff --git a/ExternalToolProjects/HelloWorld/build_release.sh b/ExternalToolProjects/HelloWorld/build_release.sh
index 89b0b361c0..73e473fcc2 120000
--- a/ExternalToolProjects/HelloWorld/build_release.sh
+++ b/ExternalToolProjects/HelloWorld/build_release.sh
@@ -1 +1 @@
-../.build_from_cwd_release.sh
\ No newline at end of file
+../.build_net48_from_cwd_release.sh
\ No newline at end of file
diff --git a/ExternalToolProjects/NET48ExternalToolForm.props b/ExternalToolProjects/NET48ExternalToolForm.props
new file mode 100644
index 0000000000..740015a650
--- /dev/null
+++ b/ExternalToolProjects/NET48ExternalToolForm.props
@@ -0,0 +1,27 @@
+<Project>
+	<PropertyGroup>
+		<TargetFramework>net48</TargetFramework>
+	</PropertyGroup>
+	<ItemGroup>
+		<PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
+		<Reference Include="System.Windows.Forms" />
+		<Reference Include="BizHawk.Client.ApiHawk"
+			HintPath="$(ProjectDir)../../output/BizHawk.Client.ApiHawk.dll"
+			Private="true" />
+		<Reference Include="BizHawk.Client.Common"
+			HintPath="$(ProjectDir)../../output/BizHawk.Client.Common.dll"
+			Private="true" />
+		<Reference Include="BizHawk.Common"
+			HintPath="$(ProjectDir)../../output/BizHawk.Common.dll"
+			Private="true" />
+		<Reference Include="BizHawk.Emulation.Common"
+			HintPath="$(ProjectDir)../../output/BizHawk.Emulation.Common.dll"
+			Private="true" />
+		<Reference Include="BizHawk.Emulation.Cores"
+			HintPath="$(ProjectDir)../../output/BizHawk.Emulation.Cores.dll"
+			Private="true" />
+		<Reference Include="BizHawk.Emulation.DiscSystem"
+			HintPath="$(ProjectDir)../../output/BizHawk.Emulation.DiscSystem.dll"
+			Private="true" />
+	</ItemGroup>
+</Project>