Guildhall Game Editor - Collision Editor
Created a way to specify convex polygons for use with the Box2D collision/physics system.  
Made sure the points were convex and saved them out into a Lua script table.  
Users are updated with a live preview of how the collision will look in game.

Guildhal Game Editor - Animation Editor
Created a way to specify animation cells.  Users will input number of rows and columns and will automatically generate row-major cells.  Users can then delete specific ones and click the preview image of the one they want to add.  Data is saved out into a Lua script table.

Johny Apple Seige - 36 Hour gamejam
Created a data driven level editor using an existing tilemap editor from the internet called Tilemapper.
This program outputs the cells location and image number and one additional integer.  It also outputs a single image of the map.
We had our designers making maps in under 2 hours while artists made modular assets for the designers.
From this we created the following pipeline.

UDK FrontEnd - I made installers for both Chroma and  Puppies In Spaaace!.  For Chroma, I also made a downloadable zip for users to create their own servers for the game with one click.

I made a trigger-able relative gravity kismet node.  Just a simple toggle for designers, but much went in under the hood.  
I also made a fly-by camera sequence for the end of matches that would trigger a camera sequence then end the game regularly after zooming in on the winning player.

Puppies In Spaaace!
I made a very nice interface for designers to explicitly tell the Scaleform HUD in UDK which image, text, and the duration of what they wanted to say.

Cell - Installer
Made an installer using NCIS installer scripts.

Cell - Mercury Particle Editor Integration
This is a processor based particle system available for download.  It inherently didn't work, but I downloaded the latest source and made some changes to their matrices and compiled a new .dll for both windows and xbox360.  This made it really easy for our artist to make the game look really good.

Cell - Level Editor
Developed a system for developers and end users to create levels for the game.  The controls were made such that developers could make levels and test them quickly.  There are no load times, and levels can be named and saved easily within the editor.

Cell - Crash Emailer - Creates a way for anyone to report a crash to an email account, they can describe what happened and more importantly it will include debug line information and the cause along with it.