On 6/22/2019 10:15 PM, Larry McVoy wrote: > I've read the Mach source. Not a fan. If you look around you can find > SunOS 4.x sources, not legal but it is out there. > If you read the Mach code, nope, it's a tangled mess, there is no > clear picture there. > > I read the papers and wanted to believe it was good, it is not. There's one thing to keep in mind about some software produced in an academic environment. Sometimes it's a collection of proofs of concept of clever ideas that various grad student have hacked together for their MS or PhD work. It's not intended to be production quality. I don't know anything about Mach, but this was certainly the state of Postgres when I worked in the Postgres group in 1991-1995. We tried to use it as the basis for a big research project (e.g. Sequoia 2000) but spent (wasted?) lots of time fighting Postgres issues. Eventually, long after I left the group, and after Mike Stonebraker left Berkeley, a group of people who weren't associated with UC Berkeley did a truly heroic job and "fixed" Postgres. The production quality Postgres you see now is the result. The BSD project was different, for all kinds of reasons. I wonder if Mach was a Postgres or BSD style project. Cordially, Jon Forrest