The old 'dsh' (distributed shell) command in DEC Ultrix gave you the ability to do something similar from the shell - kind of rsh on steroids. (FWIW, Ultrix remains my overall favorite Unix - it was very well thought-out, and just thought-about period. It's a shame they abandoned it for OSF/1 on Alpha, which never really worked (well, the DEC Alpha hardware worked, but OSF/1 and the compilers never did...)

Way back in the early 90s, inspired by this and a few other things, a coworker of mine (one of only three true geniuses I've ever met) came up with an even more powerful way (called vArray) to spread processes across any arbitrary number of POSIX machines. One of the things vArray could do was make remote memory look local (if painfully slow). He was the company's Cray expert, and developed it for the major oil company we worked for to run jobs too large to fit into the Cray's memory. Since some seismic deconvolution vectorizes very well, with fairly infrequent memory access, it worked better than you might expect, even over the slow networks of the day. Obviously, it hammered the network, but it was quite a sight to see every Sun, DEC, IBM, and HP Unix machine on the company's network light up at once, all coordinating to process jobs that were probably bigger than anything run outside the Black world of the Spooks... Fun days.

OpenMOSIX is something I miss so much. I watched people build entire functional clusters using off-the-shelf hardware in a very tight budget and in just a few hours (most of the time was just unpacking things) using network boot and (IIRC) ClusterKnoppix. It was just "fork and forget" and boom, your job was now running in multiple processors.

I'd like to do that with my spare ARM SBC's.

I think multicore CPUs did a lot to kill the momentum of OpenMOSIX. I remember playing around with clusterKNOPPIX back in the day and being quite impressed by it, but it seems that multiple cores and threads per core became the norm and the cores themselves got a lot faster.

On the other hand, combining multiple 64-core Threadrippers into a single-system-image cluster has a certain appeal to it.

Open mosix was the coolest project.