LHA

The LHA/LZH format is still the most common form of compression used in Japan. It was the common format for Amiga and Atari ST, and it was generally somewhat popular in the first early 90s. A number of archives on Download Central use it.

Best put the executable somewhere in your path. On a genuine DOS installation, the DOS directory is a good place, in DOSBox, the folder that is mounted as C. Both WinZip and WinRAR 2.06 can serve as a Windows 3.1 front end.