A large number of Microlite20-based games and Microlite20 variants have been published over the last 3 or 4 years. I was testing PDF combining programs for a client today and decided to test them by making a combined PDF holding all the free Microlite20 basic, variant, and complete game PDFs I had on my drive: over 40 plus some characters sheets and the like. There free Microlite20-based fantasy games, science fiction games, modern games, superhero games, and after the holocaust (or the zombies) games. The final PDF file was about 400 pages (and 17.5 megs because some of the PDFs had illos). I figured that after I'd created this, I might as well make it available. If you'd like to have a single PDF file with the rules for Microlite20 and many of its variants, you can download it from Mediafire via this link: [link removed as I've uploaded a revised version -- See this post: The Microlite20 RPG Collection - Revised (Free Download).]
By the way, the winning PDF Combine software (of those I tested) is also free and open source: PDF Split and Merge (PDFSAM). PDFSAM was the only software I tried that did not abort on one or more of the 50 or so files I was combining.