Don't use the packaged sources, they are outdated and have not been maintained since several months).

Use CVS and get a version from the limewire/core and limewire/gui projects, by creating two projects in your cvsroot directory: core and limewire.
then:
cd core ; ant clean ; ant ; buildCoreJar
cd ../gui ; ant clean ; ant

start the compiled version with "run" in the gui folder.