Alex Schroeder has his "Hard Core" variant of Microlite 20 up available on the web. It uses some of the ideas from my Microlite74 which makes it an interesting mash up of old school and new school. Alex lists the changes he's made to M20 and M74 in this entry on his wiki. There's a link to download a pdf of Hard Core M20 on the same page. I'm glad to see that Microlite74 is inspiring others.