In the late 1980s I wrote much of the code for my PhD in BCPL, despite C being available. It was clean, clear, and when you wrote code it was obvious what it was going to do. The type-less nature wasn't a problem, and co-routines were invaluable, bordering on indispensable.

I also assisted in bootstrapping BCPL on a self-built machine, and it was so easy. I liked it, though I'm not sure I'd go back to it.

I also chatted with Martin Richards for a while about MCPL, but never found the time to dive into that.

Fun times.