I build things from scratch to understand how they work.
olive-sh - A POSIX-ish shell written in C. FSM based lexer, recursive-descent parser, fork-all-before-wait pipelines and job control.
skiff - An HTTP server written in C using an epoll/kqueue event loop, featuring zero-copy static file serving via sendfile(), CGI and keep-alive support.
C - OCaml - Python