1) Simulation and teleprocessing 
Simtel, sometimes cited as Simtelnet, was an important long-running archive of freeware and shareware for various operating systems. The Simtel archive had significant ties to the history of several operating systems: it was in turn a major repository for CP/M, MS-DOS, Microsoft Windows and FreeBSD. The archive was hosted initially on TOPS-20, the...
Simulation and Teleprocessing