MenuetOS

MenuetOS is a PC OS written entirely in 32bit assembly language and released under the GPL. Despite being almost entirely based in 32 bit x86 assembly, it might be a nice way to revive older hardware (as well as a bit more flexible than Contiki):

Features:

  • Pre-emptive multitasking, multithreading, ring-3 protection
  • Responsive GUI with resolutions up to 1280x1024, 16 million colours
  • IDE: Editor/Macro Assembler for building kernel and applications
  • TCP/IP stack with Loopback, PPP & Ethernet drivers
  • Network applications include FTP///SMTP servers, IRC, , NNTP and TFTP clients
  • Free-form, skinnable application windows
  • Hard real-time data fetch
  • Fits uncompressed on a single floppy

Resources: