Mystic BBS – written by James Coyle with versions for Windows/Linux/ARM Linux/OSX. Past versions: MS-DOS and OS/2.
Synchronet – Windows/Linux/BSD, past versions: MS-DOS and OS/2.
WWIV – WWIV v5.x is supported on both Windows 7+ 32bit as well as Linux 32bit and 64bit.[2] Written by Wayne Bell, included WWIVNet. Past versions: MS-DOS and OS/2.