1. The music, online presence, and/or projects-in-general of any electronic musician who constantly yammers about all of their custom software/hardware projects, but never posts any actual songs.
2. Said musician himself.
Can be used as an interjection or conversationally; comedic and/or pejorative.
guy 1: "Today I'm writing more custom software for my chiptune
guy 2: "devblog"