- 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!