I've mentioned that I am working on a special version of the Microlite74/Microlite81 rules for the new old school campaign I'm planning to start in October in the few posts I've managed to make since my world fell apart in April. I finally have an early (0.15) version of these rules "finished" and I have decided to make this initial very rough draft available as a public playtest. Many future drafts will probably come out over the next couple of months -- most of the will only be released in the Donor Downloads area for RetroRoleplaying Cancer Fund Donors. Another public playtest draft should appear about the time the new campaign starts.
Fantastic Adventures combines some of the features of Microlite81 on top of a Microlite74-ish base. Some of the distinguishing features of Fantastic Adventures include: only 3 classes (Fighter, Magician, and Sorcerer -- Magician is limited to white magic and can fight and turn undead); backgrounds include race, culture, and prior "profession" (and can be used to create thieves, woodsmen, priests, etc.); only one spell list but three types of spells (white, grey, and black -- casting black magic can corrupt the caster). The final version of this game will be more of its own thing than an obvious version of M74/M81, however -- especially as it will be more complete (and therefore less "lite").
You can download a free copy of the 0.15 version of Fantastic Adventures here.