Your first question must always be: what is the most difficult part of this problem that I am trying to solve and then try and solve that. If you can… - Joe Armstrong

Processes are isolated by design. Context switching are very lightweight. The processes by design cannot damage each other.

why do we write things from scratch all the time and reimplementing things? because it's quicker than finding another programming language that does it. We can't find this program, and if we find it, it does something slightly different to the one we wanted and it's quicker to rewrite a new program than modify the old program.

One thing I wanted to do with Prolog, pick some sort of better things. Better stuff should happen when it fails. The other problem with prolog is that you could only do one thing, and you can only have one process. So I wanted and I thought Prolog was really great. I made an algebra to describe telephony in Prolog but the only trouble was you could only describe one process and if they didn't do what you'd expected them to do when you got failure, it didn't work.