Wikipedia
Darwine was a port of the Wine libraries to Darwin and Mac OS X (the Wine project provides source code for OS X but not binary builds). The Darwine project intended to port and develop Wine as well as other supporting tools that would allow Darwin and Mac OS X users to run Windows applications and to provide a Win32 API compatibility at application source code level.
Darwine is a free and open source software application that aims to allow applications designed for Microsoft Windows to run on Mac OS X operating systems. Darwine was developed from Wine which performed these functions on other Unix and Linux operating systems. Darwine also provided a software library, known as Winelib, against which developers can compile Windows applications to help port them to Unix-like systems.