TiMidity++ is described as 'open source MIDI to WAVE converter and player' and is an app in the Audio & Music category. There are three alternatives to TiMidity++ for Windows, BSD, Linux and Mac. The best alternative is FluidSynth, which is both free and Open Source. Other great apps like TiMidity++ are VirtualMIDISynth (Free) and Spesoft Audio Converter (Free).
VirtualMIDISynth is a software MIDI synthesizer implemented as a Windows multimedia user driver, accessible as a standard MIDI Out device. It works on Windows XP (SP3) / Vista (SP1) / 7 (SP1) / 8 (both x86 and x64), and is based on the great BASS library from un4seen.