The abcMIDI suite consists of programs for turning ABC music files into MIDI and vice versa, typesetting them as PostScript files, and manipulate them in several ways.
abcm2ps is a command-line program that converts ABC music notation files to sheet music in PostScript or SVG format.
SDL_bgi is a graphics library based on SDL2. SDL_bgi is nearly fully compatible with BGI (graphics.h), the Borland Graphics Interface that was the de-facto standard in PC graphics back in DOS days. It's very easy to use, pretty fast, and it also provides extensions for ARGB colours, mouse support, and turtle graphics. It should run on any platform supported by SDL2.
EasyABC is an open source ABC editor for Windows, OSX and Linux. It uses abcm2ps and abcMIDI for typesetting the score and playing the music.