I've been using LilyPond for a number of years to transcribe individual parts from choral and instrumental music. Along the way, I've tried various GUI's and editor macros but none have proved quite satisfactory --- particularly when it comes to efficiently transcribing more than one part.
I coded a solution that's made a significant improvement in the time required to transcribe multiple parts (as individual part sheets) and thought it worth sharing so I put it up on GitHub at
The README there is a comprehensive document, so I won't rehash it here.
Although I'm describing it as a 0.1 version, that's largely because I've only tested it on OS X. Otherwise, it's fairly complete and solid CLI program written in Python and should run on on Linux and probably Windows.
I'd be interested in any constructive feedback either in this thread or on GitHub.