QuArK (Quake Army Knife) is a game level editor and multi-purpose tool for games using engines similar to or based on the Quake engine by id Software. QuArK has the ability to create and directly edit maps, and to a limited extent, models, and can import, export and convert sounds, textures and various other game assets. It is also able to modify .pak and .pk3 files, as well as importing compiled BSP's in order to study the entities as well as add/change/delete entities from these files.
QuArK can support Half Life 1 through the
.map file format as well import from and export to Half Life 2's
.vmf file format.