I started building this machine in 1998, and like the old joke goes, it still isn't done. But I will say that the majority of work on this one finally came to an end in 2003, when I built my twentieth module, a dual wave shaper, based on the middle section of the Serge wave multiplier (abundantly documented on many web sites).
On the top row, the modules are: three oscillators, triple ring modulator, two dual vca's, multimod filter, serge old-style filter (no longer working, coated in epoxy, boo hoo), 4-1 mixer, and 2-1 mixer with meter. On the second row: power control, dual +-1, dual l.f. saw oscillator, dual comparator, dual clock, simple envelope generator, dual waveshaper, noise generator with sample and hold, line in/mic pre, and interface for controller.
I built it all from scratch, with mail-order and salvage parts. Most of the circuits are from the internet, though I modified a lot of them because I didn't think they worked right, or I thought I could do "better". If you want to build a modular, my advice is not to do it if you want to have any friends, it takes too much time.