florb : florb is a really simple map viewer and GPX editor written in C++ using the FLTK UI toolkit. ( http://florb.shugaa.de/ )
navit : An open-source car navigation system with a routing engine ( http://www.navit-project.org )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a booboo
For Paludis use this rsync : rsync://gentoo.zugaina.org/booboo-portage
If you have a problem : ycarus(-at-)zugaina.org