Xnoise is a GTK+ media player built with big music collections in mind. Its development started back in 2008 and unfortunately, it looks like 2014 is its final year because, according to Shuerhaaken, the Xnoise developer, the player "lost development contributors" and he doesn't have enough time to continue the project:
"I started doing xnoise in 2008 and I spent quite some time developing it and that was fun for me! With the nice and then newly created vala language, it was a great adventure to gain more experience by adding new features, speeding things up and discussing design issues.
Problem is, I lost development contributors and I wasn't able to interest others to join the development of xnoise. With me now having less time, I decided to let this project die. Anybody can fork xnoise and proceed, but I'm out. Sorry for the inconvenience.
Thanks to all helpers, contributors and translators!
On the other hand, Libtaginfo, a library for reading media metadata (tags), which was used by Xnoise and developed by the same Shuerhaaken, will not be abandoned.
Xnoise is free, open source software so even though its developer won't be maintaining it any more, it doesn't mean it's dead yet: if there are Xnoise users out there who can continue its development, contact Shuerhaaken on the Xnoise mailing list and see if you can take over the project.
Thanks to Gijs for the tip!