Wine is an implementation of the Windows API on top of X and Unix. It does not require Microsoft Windows, but can use native Windows DLLs if they are available. It provides both a development toolkit for porting Windows source code to Unix as well as a program loader, allowing many unmodified Windows programs to run on x86-based Unixes.
minor feature: Initial version of a HID-based joystick backend. Improved high-DPI theming support. More preparation work for the GDI syscall interface. Better CodeView support in WineDump. Various.