Complex sentence: MacPorts was listed as the recommended provider of recent Mac builds of GIMP prior to the release of version 2.8.2, which runs natively on Mac OS X. GTK + was originally designed to run on an X11 server.
Split into simpler sentences: MacPorts was listed as the recommended provider of Mac builds of GIMP. This is no longer needed as version 2.8.2 and later runs natively on Mac OS X. GTK + was originally designed to run on an X11 server.