Wine is an Open Source implementation of the Windows API on top of X and Unix. Wine provides both a development toolkit for porting Windows sources to Unix and a program loader, allowing many unmodified Windows binaries to run on x86-based Unixes.
I have successfully been using wine since 2013, after several years of unsuccess via Fedora Linux. I have been able to run MP3 software MusicMatch (circa 2000), and QImage (2013/14), and the IBM World Book Encyclopedia (2000). I want to run other Windows software, but even using Q4Wine it is very difficult to setup and go. I get "missing libs" errors. I want to run Caillou CD-ROM game I bought in 2004-ish. Won't run before but I'll give it another try. Still has a long way to go.