YoYo Games Ltd
Tool set for designing and creating 2D games easily.
Sally's Studio is a nice time-management game in which you manage a studio.
It helps you to take screenshots of different windows or screen areas.
Create games using pre-built resources (graphics, audio files, sprites sample).
XNA Game Studio 3.0 allows create games for Windows ans Zune players.
Create your own Freecell Games with this Freecell Game Studio.
Create your own Spider Games with this Spider Game Studio.
Tripwire Interactive, LLC
This is a major achievement from any game studio as few games.
Pixel Mine, Inc.
nFringe is an IDE for developing games; this works as an addon for Visual Studio.
DX Studio Player is a development tool for the creation of 3D video games.
With Wii Game Studio, you can make 2-dimensional games for the Nintendo Wii.
Visual RPG Studio (VRS) can be used to create games without any programming.
Roblox Studio is the program that Roblox games are played with.
Job and Esther Technologies Ltd
Eqela Studio is a professional app that allows you to create games and apps.
Visionaire Studio is a tool for the creation of point-and-click adventure games.