Inspired by a question about this: GOD & GUILD™ (working title) is still in the first draft writing stage, although it now also looks like it is merging with AEONS™. But so far it’s progressing smoothly with no major issues.
To give you a little more background, the core system is a roll-over d20 skill system. There are no classes, but characters are constrained in their skill development by their guild of choice, or their church.
A lot of the basic assumptions like spells, monsters, population densities, etc. are coming from the implied setting of OD&D, as succinctly drawn out on the eminent Semper Initiativus Unum blog.
G&G™/AEONS™, by the way, is not OGL.