[p9idf]

> The idea of never free()ing and then taking advantage of that with a dumb allocator to get better performance is pretty clever.

Ken Thompson's C compiler does this.

http://plan9.bell-labs.com/sources/plan9/sys/src/cmd/cc/comp...

http://plan9.bell-labs.com/sources/plan9/sys/src/cmd/cc/lex.... (near the end)

http://plan9.bell-labs.com/sources/plan9/sys/src/cmd/cc/macb... (near the end)