A quick search this morning reveals Chapter and Verse (for Windows) which looks like it works much the same way as AB builder:
http://lodensoftware.com/chapter-and-verse/
For Linux (more particularly Ubuntu and derivatives) theres ABC (AudioBook Creator). The website gives a list of the file dependencies and where to acquire those not automatically installed by Ubuntu.
http://www.ausge.de/ausge-download/abc-info-english