diff --git a/Ix.NET/Source/ApiCompare/ApiCompare.csproj b/Ix.NET/Source/ApiCompare/ApiCompare.csproj
index 18e24b63a0..495d7d0ead 100644
--- a/Ix.NET/Source/ApiCompare/ApiCompare.csproj
+++ b/Ix.NET/Source/ApiCompare/ApiCompare.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Ix.NET/Source/FasterLinq/FasterLinq.csproj b/Ix.NET/Source/FasterLinq/FasterLinq.csproj
index c130f44d18..74954604db 100644
--- a/Ix.NET/Source/FasterLinq/FasterLinq.csproj
+++ b/Ix.NET/Source/FasterLinq/FasterLinq.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
   </PropertyGroup>
 
 </Project>
diff --git a/Ix.NET/Source/Playground/Playground.csproj b/Ix.NET/Source/Playground/Playground.csproj
index 18e24b63a0..495d7d0ead 100644
--- a/Ix.NET/Source/Playground/Playground.csproj
+++ b/Ix.NET/Source/Playground/Playground.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Ix.NET/Source/System.Interactive.Async.Providers.Tests/System.Interactive.Async.Providers.Tests.csproj b/Ix.NET/Source/System.Interactive.Async.Providers.Tests/System.Interactive.Async.Providers.Tests.csproj
index 0ce2587493..ee9410ed15 100644
--- a/Ix.NET/Source/System.Interactive.Async.Providers.Tests/System.Interactive.Async.Providers.Tests.csproj
+++ b/Ix.NET/Source/System.Interactive.Async.Providers.Tests/System.Interactive.Async.Providers.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.1;net461;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.1;net461;netcoreapp3.1;net6.0</TargetFrameworks>
     <NoWarn>$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>
 
diff --git a/Ix.NET/Source/System.Interactive.Async.Tests/System.Interactive.Async.Tests.csproj b/Ix.NET/Source/System.Interactive.Async.Tests/System.Interactive.Async.Tests.csproj
index e57a9985fe..582d18fda5 100644
--- a/Ix.NET/Source/System.Interactive.Async.Tests/System.Interactive.Async.Tests.csproj
+++ b/Ix.NET/Source/System.Interactive.Async.Tests/System.Interactive.Async.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.1;net461;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.1;net461;netcoreapp3.1;net6.0</TargetFrameworks>
     <NoWarn>$(NoWarn);CS0618;CS8603;CS8625</NoWarn>
   </PropertyGroup>
 
diff --git a/Ix.NET/Source/System.Interactive.Providers/System.Interactive.Providers.csproj b/Ix.NET/Source/System.Interactive.Providers/System.Interactive.Providers.csproj
index e7015409d7..316251813b 100644
--- a/Ix.NET/Source/System.Interactive.Providers/System.Interactive.Providers.csproj
+++ b/Ix.NET/Source/System.Interactive.Providers/System.Interactive.Providers.csproj
@@ -17,7 +17,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\System.Interactive\System.Interactive.csproj" />
-    <ReferenceAssemblyProjectReference Include="..\refs\System.Interactive.Providers.Ref\System.Interactive.Providers.Ref.csproj" />
+    <ReferenceAssemblyProjectReference Include="..\refs\System.Interactive.Providers.Ref\System.Interactive.Providers.Ref.csproj" ReferenceOutputAssembly="false" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard1.0'">
diff --git a/Ix.NET/Source/System.Interactive.Tests/System.Interactive.Tests.csproj b/Ix.NET/Source/System.Interactive.Tests/System.Interactive.Tests.csproj
index 7cb873dc38..0c6a1ce9ab 100644
--- a/Ix.NET/Source/System.Interactive.Tests/System.Interactive.Tests.csproj
+++ b/Ix.NET/Source/System.Interactive.Tests/System.Interactive.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.1;net461</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.1;net461;net6.0</TargetFrameworks>
     <NoWarn>$(NoWarn);CS0618;CS8603;CS8625</NoWarn>
   </PropertyGroup>
 
diff --git a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/Max.cs b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/Max.cs
index 4e25027fed..b23b3d5c2c 100644
--- a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/Max.cs
+++ b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/Max.cs
@@ -11,6 +11,7 @@ namespace Tests
 {
     public class Max : Tests
     {
+#if !NET6_0_OR_GREATER
         [Fact]
         public void Max_Arguments()
         {
@@ -31,5 +32,6 @@ public int Compare(int x, int y)
                 return Comparer<int>.Default.Compare(x % 7, y % 7);
             }
         }
+#endif
     }
 }
diff --git a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/MaxBy.cs b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/MaxBy.cs
index 009bdfc8bd..6c56222c44 100644
--- a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/MaxBy.cs
+++ b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/MaxBy.cs
@@ -11,6 +11,7 @@ namespace Tests
 {
     public class MaxBy : Tests
     {
+#if !NET6_0_OR_GREATER
         [Fact]
         public void MaxBy_Arguments()
         {
@@ -33,5 +34,6 @@ public void MaxBy_Empty()
         {
             AssertThrows<InvalidOperationException>(() => Enumerable.Empty<int>().MaxBy(x => x));
         }
+#endif
     }
 }
diff --git a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/Min.cs b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/Min.cs
index 733a2eca68..f6924136de 100644
--- a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/Min.cs
+++ b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/Min.cs
@@ -11,6 +11,7 @@ namespace Tests
 {
     public class Min : Tests
     {
+#if !NET6_0_OR_GREATER
         [Fact]
         public void Min_Arguments()
         {
@@ -31,5 +32,6 @@ public int Compare(int x, int y)
                 return Comparer<int>.Default.Compare(x % 3, y % 3);
             }
         }
+#endif
     }
 }
diff --git a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/MinBy.cs b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/MinBy.cs
index 73706530a4..2b19f38e19 100644
--- a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/MinBy.cs
+++ b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/MinBy.cs
@@ -11,6 +11,7 @@ namespace Tests
 {
     public class MinBy : Tests
     {
+#if !NET6_0_OR_GREATER
         [Fact]
         public void MinBy_Arguments()
         {
@@ -33,5 +34,6 @@ public void MinBy_Empty()
         {
             AssertThrows<InvalidOperationException>(() => Enumerable.Empty<int>().MinBy(x => x));
         }
+#endif
     }
 }
diff --git a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/SkipLast.cs b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/SkipLast.cs
index 186f522552..53b56a1943 100644
--- a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/SkipLast.cs
+++ b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/SkipLast.cs
@@ -8,7 +8,7 @@
 
 namespace Tests
 {
-#if !NETCOREAPP2_1
+#if !NETCOREAPP2_1_OR_GREATER
     public class SkipLast : Tests
     {
         [Fact]
diff --git a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/TakeLast.cs b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/TakeLast.cs
index baea092bd9..d09d8b1394 100644
--- a/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/TakeLast.cs
+++ b/Ix.NET/Source/System.Interactive.Tests/System/Linq/Operators/TakeLast.cs
@@ -8,7 +8,7 @@
 
 namespace Tests
 {
-#if !NETCOREAPP2_1
+#if !NETCOREAPP2_1_OR_GREATER
     public class TakeLast : Tests
     {
         [Fact]
diff --git a/Ix.NET/Source/System.Interactive/System.Interactive.csproj b/Ix.NET/Source/System.Interactive/System.Interactive.csproj
index f3effe33a5..b3fc11fb08 100644
--- a/Ix.NET/Source/System.Interactive/System.Interactive.csproj
+++ b/Ix.NET/Source/System.Interactive/System.Interactive.csproj
@@ -10,7 +10,7 @@
 
   <ItemGroup>
     <EmbeddedResource Include="Properties\System.Interactive.rd.xml" />
-    <ReferenceAssemblyProjectReference Include="..\refs\System.Interactive.Ref\System.Interactive.Ref.csproj" />
+    <ReferenceAssemblyProjectReference Include="..\refs\System.Interactive.Ref\System.Interactive.Ref.csproj" ReferenceOutputAssembly="false" />
   </ItemGroup>
   
 </Project>
diff --git a/Ix.NET/Source/System.Interactive/System/Linq/Operators/Max.cs b/Ix.NET/Source/System.Interactive/System/Linq/Operators/Max.cs
index 4fded162a8..ca1747fb7b 100644
--- a/Ix.NET/Source/System.Interactive/System/Linq/Operators/Max.cs
+++ b/Ix.NET/Source/System.Interactive/System/Linq/Operators/Max.cs
@@ -8,6 +8,8 @@ namespace System.Linq
 {
     public static partial class EnumerableEx
     {
+
+#if !(REFERENCE_ASSEMBLY && (NET6_0))
         /// <summary>
         /// Returns the maximum value in the enumerable sequence by using the specified comparer to compare values.
         /// </summary>
@@ -24,5 +26,6 @@ public static TSource Max<TSource>(this IEnumerable<TSource> source, IComparer<T
 
             return MaxBy(source, x => x, comparer).First();
         }
+#endif
     }
 }
diff --git a/Ix.NET/Source/System.Interactive/System/Linq/Operators/MaxBy.cs b/Ix.NET/Source/System.Interactive/System/Linq/Operators/MaxBy.cs
index c6505400eb..eb074e2e6b 100644
--- a/Ix.NET/Source/System.Interactive/System/Linq/Operators/MaxBy.cs
+++ b/Ix.NET/Source/System.Interactive/System/Linq/Operators/MaxBy.cs
@@ -8,6 +8,7 @@ namespace System.Linq
 {
     public static partial class EnumerableEx
     {
+#if !(REFERENCE_ASSEMBLY && (NET6_0))
         /// <summary>
         /// Returns the elements with the maximum key value by using the default comparer to compare key values.
         /// </summary>
@@ -80,5 +81,6 @@ private static IList<TSource> ExtremaBy<TSource, TKey>(IEnumerable<TSource> sour
 
             return result;
         }
+#endif
     }
 }
diff --git a/Ix.NET/Source/System.Interactive/System/Linq/Operators/Min.cs b/Ix.NET/Source/System.Interactive/System/Linq/Operators/Min.cs
index 84726b21e6..913dcb1b2c 100644
--- a/Ix.NET/Source/System.Interactive/System/Linq/Operators/Min.cs
+++ b/Ix.NET/Source/System.Interactive/System/Linq/Operators/Min.cs
@@ -8,6 +8,7 @@ namespace System.Linq
 {
     public static partial class EnumerableEx
     {
+#if !(REFERENCE_ASSEMBLY && (NET6_0))
         /// <summary>
         /// Returns the minimum value in the enumerable sequence by using the specified comparer to compare values.
         /// </summary>
@@ -24,5 +25,6 @@ public static TSource Min<TSource>(this IEnumerable<TSource> source, IComparer<T
 
             return MinBy(source, x => x, comparer).First();
         }
+#endif
     }
 }
diff --git a/Ix.NET/Source/System.Interactive/System/Linq/Operators/MinBy.cs b/Ix.NET/Source/System.Interactive/System/Linq/Operators/MinBy.cs
index 42c088f762..d8da1b2016 100644
--- a/Ix.NET/Source/System.Interactive/System/Linq/Operators/MinBy.cs
+++ b/Ix.NET/Source/System.Interactive/System/Linq/Operators/MinBy.cs
@@ -8,6 +8,8 @@ namespace System.Linq
 {
     public static partial class EnumerableEx
     {
+
+#if !(REFERENCE_ASSEMBLY && (NET6_0))
         /// <summary>
         /// Returns the elements with the minimum key value by using the default comparer to compare key values.
         /// </summary>
@@ -46,5 +48,6 @@ public static IList<TSource> MinBy<TSource, TKey>(this IEnumerable<TSource> sour
 
             return ExtremaBy(source, keySelector, (key, minValue) => -comparer.Compare(key, minValue));
         }
+#endif
     }
 }
diff --git a/Ix.NET/Source/System.Interactive/System/Linq/Operators/SkipLast.cs b/Ix.NET/Source/System.Interactive/System/Linq/Operators/SkipLast.cs
index 3a68fb846c..52b48cfe2b 100644
--- a/Ix.NET/Source/System.Interactive/System/Linq/Operators/SkipLast.cs
+++ b/Ix.NET/Source/System.Interactive/System/Linq/Operators/SkipLast.cs
@@ -8,7 +8,7 @@ namespace System.Linq
 {
     public static partial class EnumerableEx
     {
-#if !(REFERENCE_ASSEMBLY && (NETCOREAPP2_0 || NETSTANDARD2_1))
+#if !(REFERENCE_ASSEMBLY && (NETCOREAPP2_1 || NETSTANDARD2_1))
         /// <summary>
         /// Bypasses a specified number of contiguous elements from the end of the sequence and returns the remaining elements.
         /// </summary>
diff --git a/Ix.NET/Source/System.Interactive/System/Linq/Operators/TakeLast.cs b/Ix.NET/Source/System.Interactive/System/Linq/Operators/TakeLast.cs
index fd336e7511..2ef22ff07a 100644
--- a/Ix.NET/Source/System.Interactive/System/Linq/Operators/TakeLast.cs
+++ b/Ix.NET/Source/System.Interactive/System/Linq/Operators/TakeLast.cs
@@ -8,7 +8,7 @@ namespace System.Linq
 {
     public static partial class EnumerableEx
     {
-#if !(REFERENCE_ASSEMBLY && (NETCOREAPP2_0 || NETSTANDARD2_1))
+#if !(REFERENCE_ASSEMBLY && (NETCOREAPP2_1 || NETSTANDARD2_1 ))
         /// <summary>
         /// Returns a specified number of contiguous elements from the end of the sequence.
         /// </summary>
diff --git a/Ix.NET/Source/System.Linq.Async.Queryable.Tests/System.Linq.Async.Queryable.Tests.csproj b/Ix.NET/Source/System.Linq.Async.Queryable.Tests/System.Linq.Async.Queryable.Tests.csproj
index c1175685e5..cdf1605e22 100644
--- a/Ix.NET/Source/System.Linq.Async.Queryable.Tests/System.Linq.Async.Queryable.Tests.csproj
+++ b/Ix.NET/Source/System.Linq.Async.Queryable.Tests/System.Linq.Async.Queryable.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.1;net461;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.1;net461;netcoreapp3.1;net6.0</TargetFrameworks>
     <NoWarn>$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>
 
diff --git a/Ix.NET/Source/System.Linq.Async.Tests/System.Linq.Async.Tests.csproj b/Ix.NET/Source/System.Linq.Async.Tests/System.Linq.Async.Tests.csproj
index 0fe9484812..a108f44f7a 100644
--- a/Ix.NET/Source/System.Linq.Async.Tests/System.Linq.Async.Tests.csproj
+++ b/Ix.NET/Source/System.Linq.Async.Tests/System.Linq.Async.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.1;net461;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.1;net461;netcoreapp3.1;net6.0</TargetFrameworks>
     <NoWarn>$(NoWarn);CS0618;CS8603;CS8625</NoWarn>
   </PropertyGroup>
 
diff --git a/Ix.NET/Source/refs/System.Interactive.Providers.Ref/System.Interactive.Providers.Ref.csproj b/Ix.NET/Source/refs/System.Interactive.Providers.Ref/System.Interactive.Providers.Ref.csproj
index 020dd5331c..1c1a6aac5f 100644
--- a/Ix.NET/Source/refs/System.Interactive.Providers.Ref/System.Interactive.Providers.Ref.csproj
+++ b/Ix.NET/Source/refs/System.Interactive.Providers.Ref/System.Interactive.Providers.Ref.csproj
@@ -3,8 +3,9 @@
   <PropertyGroup>
     <Description>Interactive Extensions Providers Library used to build query providers and express queries over enumerable sequences.</Description>
     <AssemblyTitle>Interactive Extensions - Providers Library</AssemblyTitle>
-    <TargetFrameworks>netstandard1.0;netcoreapp2.0;netstandard2.1</TargetFrameworks>
+    <TargetFrameworks>netstandard1.0;netcoreapp2.1;netstandard2.1</TargetFrameworks>
     <PackageTags>Ix;Interactive;Extensions;Enumerable</PackageTags>
+  <AssemblyName>System.Interactive.Providers</AssemblyName>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard1.0'">
diff --git a/Ix.NET/Source/refs/System.Interactive.Ref/System.Interactive.Ref.csproj b/Ix.NET/Source/refs/System.Interactive.Ref/System.Interactive.Ref.csproj
index 7237c5a159..26655520ba 100644
--- a/Ix.NET/Source/refs/System.Interactive.Ref/System.Interactive.Ref.csproj
+++ b/Ix.NET/Source/refs/System.Interactive.Ref/System.Interactive.Ref.csproj
@@ -3,8 +3,9 @@
   <PropertyGroup>
     <Description>Interactive Extensions Main Library used to express queries over enumerable sequences.</Description>
     <AssemblyTitle>Interactive Extensions - Main Library</AssemblyTitle>
+    <AssemblyName>System.Interactive</AssemblyName>
     <Authors>Microsoft</Authors>
-    <TargetFrameworks>netstandard1.0;netcoreapp2.0;netstandard2.1</TargetFrameworks>
+    <TargetFrameworks>netstandard1.0;netcoreapp2.1;netstandard2.1;net6.0</TargetFrameworks>
     <PackageTags>Ix;Interactive;Extensions;Enumerable</PackageTags>
   </PropertyGroup>
 
diff --git a/Ix.NET/Source/refs/System.Linq.Async.Ref/System.Linq.Async.Ref.csproj b/Ix.NET/Source/refs/System.Linq.Async.Ref/System.Linq.Async.Ref.csproj
index c7b8b28cc7..06bdb0c5db 100644
--- a/Ix.NET/Source/refs/System.Linq.Async.Ref/System.Linq.Async.Ref.csproj
+++ b/Ix.NET/Source/refs/System.Linq.Async.Ref/System.Linq.Async.Ref.csproj
@@ -6,6 +6,7 @@
     <Authors>Microsoft</Authors>
     <TargetFrameworks>net461;netstandard2.0;netstandard2.1;netcoreapp3.1</TargetFrameworks>
     <PackageTags>Enumerable;Asynchronous;LINQ</PackageTags>
+    <AssemblyName>System.Linq.Async</AssemblyName>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Ix.NET/Source/version.json b/Ix.NET/Source/version.json
index c9238a4843..9231a30c45 100644
--- a/Ix.NET/Source/version.json
+++ b/Ix.NET/Source/version.json
@@ -1,5 +1,5 @@
 {
-  "version": "5.1.0-preview.{height}",
+  "version": "5.1.0",
   "publicReleaseRefSpec": [
     "^refs/heads/main$", // we release out of main
     "^refs/heads/rel/v\\d+\\.\\d+", // we also release branches starting with vN.N
diff --git a/azure-pipelines.ix.yml b/azure-pipelines.ix.yml
index 50bcb0fe51..c5c2d1e64b 100644
--- a/azure-pipelines.ix.yml
+++ b/azure-pipelines.ix.yml
@@ -32,10 +32,15 @@ stages:
       vmImage: ubuntu-latest
     steps:
     - task: UseDotNet@2
-      displayName: Use .NET Core 5.0.x SDK
+      displayName: Use .NET Core 6.x SDK
       inputs:
-        version: 5.0.x
-        includePreviewVersions: true
+        version: 6.x
+
+    - task: UseDotNet@2
+      displayName: .NET Core 5.0 runtime
+      inputs:
+        version: '5.0.x'
+        packageType: runtime
 
     - task: UseDotNet@2
       displayName: .NET Core 3.1 runtime