diff --git a/.gitmodules b/.gitmodules
index 104d36e64..1362f1c8d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,4 +1,4 @@
 [submodule "submodules/PSScriptAnalyzer"]
 	path = submodules/PSScriptAnalyzer
 	url = https://github.com/PowerShell/PSScriptAnalyzer.git
-	branch = development
+	branch = master
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a514da788..3ca533d08 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,37 @@
 # PowerShell Editor Services Release History
 
+## 0.4.0
+### Monday, February 8, 2016
+
+#### Debugging improvements
+
+- A new `Microsoft.PowerShell.EditorServices.Host.x86.exe` executable has been added to enable 32-bit PowerShell sessions on 64-bit machines (thanks [@adamdriscoll](https://github.com/adamdriscoll)!)
+- You can now pass arguments to scripts in the debugger with the `LaunchRequest.Args` parameter (thanks [@rkeithhill](https://github.com/rkeithhill)!)
+- You can also set the working directory where the script is run by setting the `LaunchRequest.Cwd` parameter to an absolute path (thanks [@rkeithhill](https://github.com/rkeithhill)!)
+
+#### Console improvements
+
+- Improved PowerShell console output formatting and performance
+  - The console prompt is now displayed after a command is executed
+  - Command execution errors are now displayed correctly in more cases
+  - Console output now wraps at 120 characters instead of 80 characters
+  - Console output is now buffered to reduce the number of OutputEvent messages sent from the host to the editor
+
+- Added choice and input prompt support.  Prompts can be shown either through the console or natively
+  in the editor via the `powerShell/showInputPrompt` and `powerShell/showChoicePrompt` requests.
+
+#### New host command line parameters
+
+- `/logLevel:<level>`: Sets the log output level for the host.  Possible values: `Verbose`, `Normal`, `Warning`, or `Error`.
+- `/logPath:<path>`: Sets the output path for logs written while the host is running
+
+#### Other improvements
+
+- Initial work has been done to ensure support for PowerShell v3 and v4 APIs by compiling against the PowerShell
+  reference assemblies that are published on NuGet. (thanks [@adamdriscoll](https://github.com/adamdriscoll)!)
+- Initial WebSocket channel support (thanks [@adamdriscoll](https://github.com/adamdriscoll)!)
+- Removed Nito.AsyncEx dependency
+
 ## 0.3.1
 ### Thursday, December 17, 2015
 
@@ -15,15 +47,15 @@
 - Introduced a new client/server API in the Protocol project which makes it
   much easier to write a client or server for the language and debugging services
 - Introduced a new channel model which makes it much easier to add and consume
-  new protocol channel implementations  
+  new protocol channel implementations
 - Major improvements in variables retrieved from the debugging service:
   - Global and script scope variables are now accessible
   - New "Autos" scope which shows only the variables defined within the current scope
   - Greatly improved representation of variable values, especially for dictionaries and
     objects that implement the ToString() method
-- Added new "Expand Alias" command which resolves command aliases used in a file or 
+- Added new "Expand Alias" command which resolves command aliases used in a file or
   selection and updates the source text with the resolved command names
-- Reduced default Script Analyzer rules to a minimal list    
+- Reduced default Script Analyzer rules to a minimal list
 - Improved startup/shutdown behavior and logging
 - Fixed a wide array of completion text replacement bugs
 
diff --git a/README.md b/README.md
index 58fb6b1de..b0236a9c0 100644
--- a/README.md
+++ b/README.md
@@ -2,8 +2,8 @@
 
 [![Build status](https://ci.appveyor.com/api/projects/status/85tyhckawwxoiim2/branch/master?svg=true)](https://ci.appveyor.com/project/PowerShell/powershelleditorservices/branch/master)
 
-PowerShell Editor Services provides common functionality that is needed 
-to enable a consistent and robust PowerShell development experience 
+PowerShell Editor Services provides common functionality that is needed
+to enable a consistent and robust PowerShell development experience
 across multiple editors.
 
 ## Features
@@ -51,3 +51,12 @@ git submodule update
 We would love to incorporate community contributions into this project.  If you would like to
 contribute code, documentation, tests, or bug reports, please read our [Contribution Guide]
 (docs/contributing.md) to learn more.
+
+## Maintainers
+
+- [David Wilson](https://github.com/daviwil) - [@daviwil](http://twitter.com/daviwil)
+- [Keith Hill](https://github.com/rkeithhill) - [@r_keith_hill](http://twitter.com/r_keith_hill)
+
+## License
+
+This project is [licensed under the MIT License](LICENSE.txt).
\ No newline at end of file
diff --git a/appveyor.yml b/appveyor.yml
index 1fea091bd..e2257a586 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -4,7 +4,7 @@ configuration: Release
 clone_depth: 10
 
 environment:
-  core_version: '0.3.1'
+  core_version: '0.4.0'
   prerelease_name: '-beta'
 
 branches:
diff --git a/submodules/PSScriptAnalyzer b/submodules/PSScriptAnalyzer
index 297140f0d..a09b0156a 160000
--- a/submodules/PSScriptAnalyzer
+++ b/submodules/PSScriptAnalyzer
@@ -1 +1 @@
-Subproject commit 297140f0d3f1205da010073cd2ad8ab8cd43b665
+Subproject commit a09b0156ac5004241ddc34b3fc4c6c5323b35dd6