Note: GTK Radiant 1.6 changed its file format, meaning that the OA pack that allows the editor to show OpenArena in the list of available games without having to manually modify configuration files, works with NetRadiant 1.5 and GTK Radiant 1.5, but NOT with GTK Radiant 1.6. You can however use the updated BSPC tool that comes with GTK Radiant 1.6, to compile .AAS files.