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 the Android graphics driver. Dictionary support in WebServices. A number of Direct2D. User interface improvements in RegEdit. OLE clipboard cache. Various.