ABC support in Score is achieved by using abc2ly, but abc2ly is imperfect: there is a lot of ABC syntax it doesn't understand. I looked at the source of Score, and the assumption that the image will be always built with Lilypond runs throughout the extension. But I think Score could be modified to support more than one rendering engine. The current workflow of: "(1) coerce the source to Lilypond, (2) use Lilypond" could be changed to "(1) given the language the score is in, find the best suitable backend and coerce the source to it, (2) use that backend". This would use abcm2ps for ABC if possible, otherwise it would use abc2ly+lilypond. Would this be a sensible change to Score?