glBSP is a node builder for , developed by Andrew J. Apted with collaboration from Jānis Legzdiņš, derived from BSP. It is available under the GNU GPL v2. There are both command-line (glbsp) and windowed (glBSPX) versions of the program in the package. glBSP can either insert the GL nodes in the map WAD, or create an external .GWA file. The node builder supports GL nodes v1, v2, v3, and v5; but not v4 which is exclusive to DeePBSP. GL nodes v1, v3, and v4 are officially deprecated formats.