Playsurface software is currently being developed using Stencyl, Flash, and Unity. In Unity, we have been making use of TouchScript, which has nice built-in gesture recognition and is easy to use. Stencyl is a block language, great for non-programmers, similar to Scratch. We have created a special extension that adds blocks to Stencyl to manage touch inputs on the Playsurface.
We are actively working on BigBlobby, and have made many improvements especially for Playsurface use. The most current version will always be available here. We've also developed the Playsurface Launcher, which acts as a sort of touch operating system. Apps can very easily be added or deleted. You can also insert a thumb drive containing your apps into a Playsurface (running the Launcher), and it will automatically load them - kind of like a game cartridge.
We are also posting both apps (executable games) and the projects (full source code in either Stencyl or Unity) that made them, so that you have some examples to work from.
Some of the code is messy, but we have been focusing mostly on getting things out there than keeping things neat. We will clean it up later, I promise!
If you create any apps of your own, please share them with the rest of us!