SIMH is a framework and family of computer simulators, initiated by Bob Supnik and continued with contributions (large and small) from many others, with the primary goal of enabling the preservation of knowledge contained in, and providing the ability to execute/experience, old/historic software via simulation of the hardware on which it ran.
In this way, we hope that modern users can experience a taste of the past and learn from those times to better understand today's systems. Many features and operations we take for granted came from these systems and made sense as they mapped to the economics of the software and hardware that was available then.
We believe that this goal has been successfully achieved and has for these years created a diverse community of users and developers.
Please visit https://opensimh.org for more information about the project.