The 100mm standard is a composing structure configured around 100mm tall by 50mm wide pcb panels. Primarily envisioned as a timing environment for control of synthesis, it can also be used as a complex pulse wave based sound source. The seed for this was the Clavia Nord Modular virtual modular environment; liking the call up of modules for a particular use but not the digital re-creation of certain analogue circuitry I have manufactured a physical hardware version. I devised an acrylic panel with bipolar supply pins, into which the panels can be plugged as needed. The only standard that needs to be adhered to is the specific pin layout of the modules and the measurement between them. A little inaccuracy in the pin spacing during home construction actually improves the connectivity.
The particular panel modules I have constructed for the 100mm standard are as follows: