In addition to the original BASIC games, versions of Hunt the Wumpus have been created for numerous other systems. Yob had seen or heard of versions in several languages, such as IBM RPG and Fortran, by 1975.[1] A version in C, written in November 1973 by Ken Thompson, creator of the Unix operating system, was released in 1974; a later C version can still be found in the bsdgames package on modern BSD and Linux operating systems.[11][12][13] A version was released for the HP-41C calculator in 1981,[14] and a commercial port for the TI-99/4A home computer was published by Texas Instruments in 1980, with graphics and a torus shape of caves displayed in a grid pattern instead of a dodecahedron.[15]