LHA LHA is the second version of LHARC for DOS. The LHA format is supported on the Amiga in the form of the "-lh5-" compression modes supported by LZ, LX, and LhA. Most popular compression programs in use today were originally based on the source code or ideas of "AR002" (an LHA compatible program), although most programs have advanced since then. Author: Haruyasu Yoshizaki