Liquorice

Liquorice was a very small operating system and IPv4 network stack, written entirely from scratch. It was designed to run on 8-bit Atmel AVR and 32-bit x86 processors.

The project ran through much of 2000, but I stopped working on the public version when I joined Ubicom at the end of 2000. The project evolved as a commercial operating system and network stack called ipOS. While ipOS started out very similar to Liquorice, it quickly diverged as we simplified concepts eliminated the software threading, and implemented much better design patterns to support some of the networking. Liquorice has some interesting ideas, and has a very small IP stack.