They Linux executables were built on a 32-bit Fedora 3 machine, and require (the common libraries) GTK+ 2 and libxml2 to be installed on your system.
The linux64 builds are 64-bit, and were built on a 64-bit Fedora 3 machine. They ofcourse require a 64-bit system to run.
Simply run the launch script after extracting the tar file for any application.