In the early 2000s I wrote a Java webapp framework called Maverick that had a brief moment of popularity (even getting community ports to PHP and .Net). In 2003 some unknown guy emailed me and asked if he could use Maverick as the framework for a book he was writing. I said sure - but he wanted me to make a lot of changes, and at the time I was focused on app development and didn't want to invest a lot more time doing open source work. So he ended up building his own framework from scratch.

The guy's name was Rod Johnson, the book was Expert One-on-One J2EE, and the framework it launched was Spring.