These ebuilds come from http://overlays.gentoo.org/proj/java.
If you have some problems, go to the official site first.
jripper : jRipper, a Java frontend to CD ripper and encoder tools ( http://dronten.googlepages.com/jripper )
jsynthlib : Java-based MIDI hardware SysEx librarian ( http://www.jsynthlib.org/ )
tuxguitar : TuxGuitar is a multitrack guitar tablature editor and player written in Java-SWT ( http://www.tuxguitar.com.ar/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a zugaina
For Paludis use this rsync : rsync://gentoo.zugaina.org/zugaina-portage
If you have a problem : ycarus(-at-)zugaina.org