sunjam Casper Electronics, by Peter Edwards, now builds for Bastl. Open hardware and extensive notes still available in Wayback Machine!!!!! Dr Bleep Devices page and Github Workshops sometimes available online through Austin Community College Eric Archer, now known as the company Rare Waves. Check out IR-sync based Space Rocker series from the early 2000's Gieskes Music From Outer Space, by Ray Wilson, RIP. Ciat Lonbarde by Peter Blasser 4ms Company Wayback Machine archive of their site from when primary focus was around open source pedals, and early development in modular synthesis Github Meeblip - Slamming, affordable desktop synthesis Sonic Potions, makers of the LXR Drum Machine, now produced by Erica Synths. There are many, many more. This is a very, very small sampling of some excellent builders.