Raptor is a top quality chess client written in Java and available under a BSD license:
Raptor stands head and shoulders above the clients already available in Portage, in having all of the following in one:
1) A highly attractive interface.
2) Full FICS support
3) Full pre-move functionality
4) BeanShell scripting support
I have not built Raptor from source myself, but I ran the generic 64-bit Linux package on my amd64 Gentoo box, and it works great under IcedTea-18.104.22.168.
Created attachment 357048 [details]
raptor chess ebuild
I've made one, it's really beta, so if anyone wants to patch it, feel free to do it.