, the makers of the successful indie game World of Goo
just released their 'Rapid Prototyping Framework
' as open source. Basically, this is the code base they used to create World of Goo: It can render 2D graphics, read input from a variety of devices, and play sounds. It includes a resource manager for loading/unloading resources, a persistence layer for saving game states, and even a file access abstraction layer.
Download it here