diff --git a/src/Microsoft.DotNet.Interactive.ApiCompatibility.Tests/ApiCompatibilityTests.Document_api_is_not_changed.approved.txt b/src/Microsoft.DotNet.Interactive.ApiCompatibility.Tests/ApiCompatibilityTests.Document_api_is_not_changed.approved.txt
index b42b37f35c..b2b7a3bdf0 100644
--- a/src/Microsoft.DotNet.Interactive.ApiCompatibility.Tests/ApiCompatibilityTests.Document_api_is_not_changed.approved.txt
+++ b/src/Microsoft.DotNet.Interactive.ApiCompatibility.Tests/ApiCompatibilityTests.Document_api_is_not_changed.approved.txt
@@ -31,6 +31,7 @@ Microsoft.DotNet.Interactive.Documents
     public System.Collections.Generic.IAsyncEnumerable<InteractiveDocument> GetImportsAsync(System.Boolean recursive = False)
     public System.Collections.Generic.IEnumerable<InputField> GetInputFields()
     public System.Collections.Generic.IEnumerable<System.String> GetMagicCommandLines()
+    public System.Boolean TryGetKernelInfosFromMetadata(ref KernelInfoCollection& kernelInfos)
   public class InteractiveDocumentElement
     .ctor()
     .ctor(System.String contents = null, System.String kernelName = null, System.Collections.Generic.IEnumerable<InteractiveDocumentOutputElement> outputs = null)
@@ -60,14 +61,13 @@ Microsoft.DotNet.Interactive.Documents
     public System.Boolean Contains(System.String nameOrAlias)
     public System.Void CopyTo(KernelInfo[] array, System.Int32 arrayIndex)
     public System.Boolean Remove(KernelInfo item)
-    public System.Boolean TryGetByAlias(System.String alias, ref KernelInfo& info)
   public class ReturnValueElement : InteractiveDocumentOutputElement, IDataElement
-    .ctor(System.Collections.Generic.IDictionary<System.String,System.Object> data)
+    .ctor()
     public System.Collections.Generic.IDictionary<System.String,System.Object> Data { get;}
     public System.Int32 ExecutionOrder { get; set;}
     public System.Collections.Generic.IDictionary<System.String,System.Object> Metadata { get;}
   public class TextElement : InteractiveDocumentOutputElement
-    .ctor(System.String text, System.String name)
+    .ctor(System.String text, System.String name = stdout)
     public System.String Name { get;}
     public System.String Text { get;}
 Microsoft.DotNet.Interactive.Documents.Jupyter
@@ -75,15 +75,8 @@ Microsoft.DotNet.Interactive.Documents.Jupyter
     .ctor(System.String kernelName = null, System.String language = null)
     public System.String KernelName { get;}
     public System.String Language { get;}
-  public static class InteractiveDocumentExtensions
-    public static Microsoft.DotNet.Interactive.Documents.InteractiveDocument WithJupyterMetadata(System.String language = C#)
   public static class Notebook
-    public static System.Text.Encoding Encoding { get;}
-    public static System.Text.Json.JsonSerializerOptions JsonSerializerOptions { get;}
     public static Microsoft.DotNet.Interactive.Documents.InteractiveDocument Parse(System.String json, Microsoft.DotNet.Interactive.Documents.KernelInfoCollection kernelInfos = null)
     public static Microsoft.DotNet.Interactive.Documents.InteractiveDocument Read(System.IO.Stream stream, Microsoft.DotNet.Interactive.Documents.KernelInfoCollection kernelInfos)
     public static System.String ToJupyterJson(System.String defaultLanguage = null)
-    public static System.Void Write(Microsoft.DotNet.Interactive.Documents.InteractiveDocument document, System.IO.Stream stream)
     public static System.Void Write(Microsoft.DotNet.Interactive.Documents.InteractiveDocument document, System.IO.Stream stream, Microsoft.DotNet.Interactive.Documents.KernelInfoCollection kernelInfos)
-    public static System.Void Write(Microsoft.DotNet.Interactive.Documents.InteractiveDocument document, System.IO.TextWriter writer)
-    public static System.Void Write(Microsoft.DotNet.Interactive.Documents.InteractiveDocument document, System.IO.TextWriter writer, Microsoft.DotNet.Interactive.Documents.KernelInfoCollection kernelInfos)
diff --git a/src/Microsoft.DotNet.Interactive.Documents.Tests/JupyterFormatTests.cs b/src/Microsoft.DotNet.Interactive.Documents.Tests/JupyterFormatTests.cs
index ffa54378b2..2c4b01a836 100644
--- a/src/Microsoft.DotNet.Interactive.Documents.Tests/JupyterFormatTests.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents.Tests/JupyterFormatTests.cs
@@ -88,7 +88,7 @@ public void notebook_metadata_default_language_is_honored_in_cells_without_langu
     [InlineData("PowerShell", "powershell")]
     public void Metadata_default_kernel_name_is_based_on_specified_language(string languageName, string kernelName)
     {
-        var document = new InteractiveDocument().WithJupyterMetadata(languageName);
+        var document = Notebook.Parse(new InteractiveDocument().ToJupyterJson(languageName));
 
         document.GetDefaultKernelName()
                 .Should()
@@ -102,7 +102,7 @@ public void Metadata_default_kernel_name_is_based_on_specified_language(string l
     [InlineData("PowerShell", "powershell")]
     public void Metadata_default_kernel_name_is_based_on_specified_language_when_serialized_and_deserialized(string languageName, string kernelName)
     {
-        var originalDoc = new InteractiveDocument().WithJupyterMetadata(languageName);
+        var originalDoc = Notebook.Parse(new InteractiveDocument().ToJupyterJson(languageName));
 
         var parsedDoc = Notebook.Parse(originalDoc.ToJupyterJson());
 
diff --git a/src/Microsoft.DotNet.Interactive.Documents/CodeSubmission.cs b/src/Microsoft.DotNet.Interactive.Documents/CodeSubmission.cs
index f26651a30b..5a8e08b280 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/CodeSubmission.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/CodeSubmission.cs
@@ -53,7 +53,7 @@ public static InteractiveDocument Parse(
 
                 metadata = JsonSerializer.Deserialize<Dictionary<string, object>>(metadataString, InteractiveDocument.JsonSerializerOptions);
 
-                if (InteractiveDocument.TryGetKernelInfoFromMetadata(metadata, out var kernelInfoFromMetadata))
+                if (InteractiveDocument.TryGetKernelInfosFromMetadata(metadata, out var kernelInfoFromMetadata))
                 {
                     InteractiveDocument.MergeKernelInfos(kernelInfos, kernelInfoFromMetadata);
                     document.Metadata["kernelInfo"] = kernelInfoFromMetadata;
diff --git a/src/Microsoft.DotNet.Interactive.Documents/InteractiveDocument.cs b/src/Microsoft.DotNet.Interactive.Documents/InteractiveDocument.cs
index 68e60d3637..4498dc1de3 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/InteractiveDocument.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/InteractiveDocument.cs
@@ -65,7 +65,7 @@ public async IAsyncEnumerable<InteractiveDocument> GetImportsAsync(bool recursiv
     {
         EnsureImportFieldParserIsInitialized();
 
-        if (!TryGetKernelInfoFromMetadata(Metadata, out var kernelInfos))
+        if (!TryGetKernelInfosFromMetadata(out var kernelInfos))
         {
             kernelInfos = new();
         }
@@ -198,7 +198,7 @@ public static async Task<InteractiveDocument> LoadAsync(
 
     public string? GetDefaultKernelName()
     {
-        if (TryGetKernelInfoFromMetadata(Metadata, out var kernelInfo))
+        if (TryGetKernelInfosFromMetadata(Metadata, out var kernelInfo))
         {
             return kernelInfo.DefaultKernelName;
         }
@@ -208,16 +208,11 @@ public static async Task<InteractiveDocument> LoadAsync(
 
     internal string? GetDefaultKernelName(KernelInfoCollection kernelInfos)
     {
-        if (TryGetKernelInfoFromMetadata(Metadata, out var kernelInfoCollection))
+        if (TryGetKernelInfosFromMetadata(Metadata, out var kernelInfoCollection))
         {
             return kernelInfoCollection.DefaultKernelName;
         }
 
-        if (Metadata is null)
-        {
-            return null;
-        }
-
         if (Metadata.TryGetValue("kernelspec", out var kernelspecObj))
         {
             if (kernelspecObj is IDictionary<string, object> kernelspecDict)
@@ -243,7 +238,7 @@ public static async Task<InteractiveDocument> LoadAsync(
 
     internal static void MergeKernelInfos(InteractiveDocument document, KernelInfoCollection kernelInfos)
     {
-        if (TryGetKernelInfoFromMetadata(document.Metadata, out var kernelInfoCollection))
+        if (TryGetKernelInfosFromMetadata(document.Metadata, out var kernelInfoCollection))
         {
             MergeKernelInfos(kernelInfoCollection, kernelInfos);
         }
@@ -264,19 +259,23 @@ internal static void MergeKernelInfos(KernelInfoCollection destination, KernelIn
         destination.AddRange(source.Where(ki => added.Add(ki.Name)));
     }
 
-    internal static bool TryGetKernelInfoFromMetadata(
+    public bool TryGetKernelInfosFromMetadata(
+        [NotNullWhen(true)] out KernelInfoCollection? kernelInfos) =>
+        TryGetKernelInfosFromMetadata(Metadata, out kernelInfos);
+
+    internal static bool TryGetKernelInfosFromMetadata(
         IDictionary<string, object>? metadata,
-        [NotNullWhen(true)] out KernelInfoCollection? kernelInfo)
+        [NotNullWhen(true)] out KernelInfoCollection? kernelInfos)
     {
         if (metadata is not null)
         {
             if (metadata.TryGetValue("kernelInfo", out var kernelInfoObj))
             {
                 if (kernelInfoObj is JsonElement kernelInfoJson &&
-                    JsonSerializer.Deserialize<KernelInfoCollection>(kernelInfoJson, JsonSerializerOptions) is
+                    kernelInfoJson.Deserialize<KernelInfoCollection>(JsonSerializerOptions) is
                         { } kernelInfoDeserialized)
                 {
-                    kernelInfo = kernelInfoDeserialized;
+                    kernelInfos = kernelInfoDeserialized;
                     return true;
                 }
 
@@ -319,7 +318,7 @@ internal static bool TryGetKernelInfoFromMetadata(
                                     deserializedKernelInfo.Add(new KernelInfo(name, language, aliases));
                                 }
                             }
-                            kernelInfo = deserializedKernelInfo;
+                            kernelInfos = deserializedKernelInfo;
                             return true;
                         }
                     }
@@ -327,7 +326,7 @@ internal static bool TryGetKernelInfoFromMetadata(
 
                 if (kernelInfoObj is KernelInfoCollection kernelInfoCollection)
                 {
-                    kernelInfo = kernelInfoCollection;
+                    kernelInfos = kernelInfoCollection;
                     return true;
                 }
             }
@@ -338,17 +337,17 @@ internal static bool TryGetKernelInfoFromMetadata(
                 {
                     case KernelInfoCollection kernelInfoCollection:
 
-                        kernelInfo = kernelInfoCollection;
+                        kernelInfos = kernelInfoCollection;
                         return true;
 
                     case IDictionary<string, object> dotnetInteractiveDict:
                         {
-                            kernelInfo = new();
+                            kernelInfos = new();
 
                             if (dotnetInteractiveDict.TryGetValue("defaultKernelName", out var nameObj) &&
                                 nameObj is string name)
                             {
-                                kernelInfo.DefaultKernelName = name;
+                                kernelInfos.DefaultKernelName = name;
                             }
 
                             return true;
@@ -364,7 +363,7 @@ internal static bool TryGetKernelInfoFromMetadata(
                     if (kernelspecDict.TryGetValue("language", out var languageObj) &&
                         languageObj is string defaultLanguage)
                     {
-                        kernelInfo = new KernelInfoCollection
+                        kernelInfos = new KernelInfoCollection
                         {
                             DefaultKernelName = defaultLanguage
                         };
@@ -375,7 +374,7 @@ internal static bool TryGetKernelInfoFromMetadata(
         }
 
         // check if a KernelInfoCollection was directly serialized into the metadata
-        kernelInfo = default;
+        kernelInfos = default;
         return false;
     }
 
diff --git a/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InputCellMetadata.cs b/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InputCellMetadata.cs
index 4a595a7161..71ca809e4f 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InputCellMetadata.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InputCellMetadata.cs
@@ -7,12 +7,15 @@ namespace Microsoft.DotNet.Interactive.Documents.Jupyter;
 
 public class InputCellMetadata
 {
-    public InputCellMetadata(string? kernelName = null, string ? language = null)
+    public InputCellMetadata(string? kernelName = null, string? language = null)
     {
         KernelName = kernelName;
         Language = language;
     }
 
-    [JsonPropertyName("kernelName")] public string? KernelName { get; }
-    [JsonPropertyName("language")] public string? Language { get; }
+    [JsonPropertyName("kernelName")] 
+    public string? KernelName { get; }
+
+    [JsonPropertyName("language")] 
+    public string? Language { get; }
 }
diff --git a/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InteractiveDocumentExtensions.cs b/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InteractiveDocumentExtensions.cs
index 6f8ed91d35..abcbcf8a35 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InteractiveDocumentExtensions.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InteractiveDocumentExtensions.cs
@@ -7,7 +7,7 @@
 
 namespace Microsoft.DotNet.Interactive.Documents.Jupyter;
 
-public static class InteractiveDocumentExtensions
+internal static class InteractiveDocumentExtensions
 {
     public static InteractiveDocument WithJupyterMetadata(
         this InteractiveDocument document,
diff --git a/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InteractiveDocumentOutputElementConverter.cs b/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InteractiveDocumentOutputElementConverter.cs
index a87d58f062..7c7419ed09 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InteractiveDocumentOutputElementConverter.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/Jupyter/InteractiveDocumentOutputElementConverter.cs
@@ -97,11 +97,16 @@ public override InteractiveDocumentOutputElement Read(
                         break;
 
                     case "execute_result":
-                        var returnValueElement = new ReturnValueElement(data ?? new Dictionary<string, object>())
+                        var returnValueElement = new ReturnValueElement
                         {
                             ExecutionOrder = executionCount ?? 0
                         };
-                        
+
+                        if (data is not null)
+                        {
+                            returnValueElement.Data.MergeWith(data);
+                        }
+
                         if (metadata is not null)
                         {
                             returnValueElement.Metadata.MergeWith(metadata);
diff --git a/src/Microsoft.DotNet.Interactive.Documents/Jupyter/Notebook.cs b/src/Microsoft.DotNet.Interactive.Documents/Jupyter/Notebook.cs
index 13ad5124d3..c5c953698c 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/Jupyter/Notebook.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/Jupyter/Notebook.cs
@@ -13,6 +13,8 @@ namespace Microsoft.DotNet.Interactive.Documents.Jupyter;
 
 public static class Notebook
 {
+    private static readonly Encoding _encoding = new UTF8Encoding(false);
+
     static Notebook()
     {
         JsonSerializerOptions = new JsonSerializerOptions
@@ -33,12 +35,7 @@ static Notebook()
         };
     }
 
-    public static JsonSerializerOptions JsonSerializerOptions { get; }
-
-    public const string MetadataNamespace = "dotnet_interactive";
-    public const string PolyglotMetadataNamespace = "polyglot_notebook";
-
-    public static Encoding Encoding => new UTF8Encoding(false);
+    internal static JsonSerializerOptions JsonSerializerOptions { get; }
 
     public static InteractiveDocument Parse(
         string json,
@@ -59,24 +56,11 @@ public static InteractiveDocument Read(
         Stream stream,
         KernelInfoCollection kernelInfos)
     {
-        using var reader = new StreamReader(stream, Encoding);
+        using var reader = new StreamReader(stream, _encoding);
         var content = reader.ReadToEnd();
         return Parse(content, kernelInfos);
     }
 
-    public static void Write(InteractiveDocument document, Stream stream)
-    {
-        using var writer = new StreamWriter(stream, Encoding, 1024, true);
-        Write(document, writer);
-        writer.Flush();
-    }
-
-    public static void Write(InteractiveDocument document, Stream stream, KernelInfoCollection kernelInfos)
-    {
-        InteractiveDocument.MergeKernelInfos(document, kernelInfos);
-        Write(document, stream);
-    }
-
     public static string ToJupyterJson(
         this InteractiveDocument document,
         string? defaultLanguage = null)
@@ -97,15 +81,12 @@ public static string ToJupyterJson(
         return singleSpaceIndentedJson;
     }
 
-    public static void Write(InteractiveDocument document, TextWriter writer)
+    public static void Write(InteractiveDocument document, Stream stream, KernelInfoCollection kernelInfos)
     {
+        InteractiveDocument.MergeKernelInfos(document, kernelInfos);
+        using var writer = new StreamWriter(stream, _encoding, 1024, true);
         var content = document.ToJupyterJson();
         writer.Write(content);
+        writer.Flush();
     }
-    public static void Write(InteractiveDocument document, TextWriter writer, KernelInfoCollection kernelInfos)
-    {
-        InteractiveDocument.MergeKernelInfos(document, kernelInfos);
-        Write(document, writer);
-    }
-
 }
\ No newline at end of file
diff --git a/src/Microsoft.DotNet.Interactive.Documents/KernelInfoCollection.cs b/src/Microsoft.DotNet.Interactive.Documents/KernelInfoCollection.cs
index 212e1dafd3..04059de5b4 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/KernelInfoCollection.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/KernelInfoCollection.cs
@@ -99,7 +99,7 @@ public KernelInfoCollection Clone()
         return clone;
     }
 
-    public bool TryGetByAlias(string alias, out KernelInfo info)
+    internal bool TryGetByAlias(string alias, out KernelInfo info)
     {
         return _kernelInfoByNameOrAlias!.TryGetValue(alias, out info);
     }
diff --git a/src/Microsoft.DotNet.Interactive.Documents/ReturnValueElement.cs b/src/Microsoft.DotNet.Interactive.Documents/ReturnValueElement.cs
index 62739f1fb3..acfb5cf66a 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/ReturnValueElement.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/ReturnValueElement.cs
@@ -1,20 +1,14 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
-using System;
 using System.Collections.Generic;
 
 namespace Microsoft.DotNet.Interactive.Documents;
 
 public class ReturnValueElement : InteractiveDocumentOutputElement, IDataElement
 {
-    public ReturnValueElement(IDictionary<string, object>? data)
-    {
-        Data = data ?? throw new ArgumentNullException(nameof(data));
-    }
+    public IDictionary<string, object> Data { get; } = new Dictionary<string, object>();
 
-    public IDictionary<string, object> Data { get; }
-    
     public int ExecutionOrder { get; set; }
 
     public IDictionary<string, object> Metadata { get; } = new Dictionary<string, object>();
diff --git a/src/Microsoft.DotNet.Interactive.Documents/TextElement.cs b/src/Microsoft.DotNet.Interactive.Documents/TextElement.cs
index 2c1ae5aaee..625e661aec 100644
--- a/src/Microsoft.DotNet.Interactive.Documents/TextElement.cs
+++ b/src/Microsoft.DotNet.Interactive.Documents/TextElement.cs
@@ -5,7 +5,7 @@ namespace Microsoft.DotNet.Interactive.Documents;
 
 public class TextElement : InteractiveDocumentOutputElement
 {
-    public TextElement(string? text, string? name)
+    public TextElement(string? text, string? name = "stdout")
     {
         Text = text ?? "";
         Name = name ?? "stdout";
diff --git a/src/Microsoft.DotNet.Interactive.Jupyter/JupyterRequestContextExtensions.cs b/src/Microsoft.DotNet.Interactive.Jupyter/JupyterRequestContextExtensions.cs
index a46dd41fcd..06bcb0bdf7 100644
--- a/src/Microsoft.DotNet.Interactive.Jupyter/JupyterRequestContextExtensions.cs
+++ b/src/Microsoft.DotNet.Interactive.Jupyter/JupyterRequestContextExtensions.cs
@@ -10,13 +10,17 @@ public static class JupyterRequestContextExtensions
     public static string GetKernelName(this JupyterRequestContext context)
     {
         string kernelName = null;
-        if (context.JupyterRequestMessageEnvelope.MetaData.TryGetValue(Notebook.MetadataNamespace, out var candidateDotnetMetadata) &&
+        if (context.JupyterRequestMessageEnvelope.MetaData.TryGetValue(
+                "dotnet_interactive", 
+                out var candidateDotnetMetadata) &&
             candidateDotnetMetadata is InputCellMetadata dotnetMetadata)
         {
             kernelName = dotnetMetadata.Language;
         }
 
-        if (context.JupyterRequestMessageEnvelope.MetaData.TryGetValue(Notebook.PolyglotMetadataNamespace, out var candidatePolyglotMetadata) &&
+        if (context.JupyterRequestMessageEnvelope.MetaData.TryGetValue(
+                "polyglot_notebook", 
+                out var candidatePolyglotMetadata) &&
             candidatePolyglotMetadata is InputCellMetadata polyglotMetadata)
         {
             kernelName = polyglotMetadata.KernelName;