After many years in development, SDL 2.0.0 has finally been released!
Ryan has put together an introduction to migrating your existing SDL application to 2.0:
More extensive documentation can be found on the community supported wiki:
Valve uses SDL 2.0 for game controller support and sundry other things in Steam, and the new release will be going into the Steam Linux Runtime in the next day or so.
These are the most important new features in SDL 2.0:
* Full 3D hardware acceleration
* Support for OpenGL 3.0+ in various profiles (core, compatibility, debug, robust, etc)
* Support for OpenGL ES
* Support for multiple windows
* Support for multiple displays
* Support for multiple audio devices
* Android and iOS support
* Simple 2D rendering API that can use Direct3D, OpenGL, OpenGL ES, or software rendering behind the scenes
* Force Feedback available on Windows, Mac OS X and Linux
* XInput and XAudio2 support for Windows
* Atomic operations
* Power management (exposes battery life remaining, etc)
* Shaped windows
* 32-bit audio (int and float)
* Simplified Game Controller API (the Joystick API is still here, too!)
* Touch support (multitouch, gestures, etc)
* Better fullscreen support
* Better keyboard support (scancodes vs keycodes, etc).
* Message boxes
* Clipboard support
* Basic Drag'n'Drop support
* Proper unicode input and IME support
* A really powerful assert macro
* Lots of old annoyances from 1.2 are gone
* Many other things!