AdlMIDI is a command line program that plays MIDI files using software OPL3 emulation (FM synthesis). It has a console UI. It features a built-in selection of 50 patch sets, most of which are General MIDI compatible, but some of which are customized for playing original background music soundtracks of select PC games.
RSound is a simplistic and lightweight framework for networked TCP/IP audio. It is designed to be very simple to implement, and to work well with music and video players. A librsound is supplied. It is not designed for low latency audio (games), and lets the sound backend take care of sound mixing. It supports POSIX-compliant systems (including cygwin). It includes audio output support for ALSA, OSS, libao, and PortAudio.