Mutable Instruments is all about open source. Schematic diagrams, board layouts, panel designs, firmware, and so forth for all their Eurorack modules as well as other hardware products may be found on Github. Everything seems to be licensed GPL3.0, MIT license, or cc-by-sa-3.0.
One little difficulty: It appears all the schematics and PCB layouts were done in an older version of EAGLE.
Before 2017, EAGLE was free for individual, non-commercial use, with some not very onerous feature limits. Now it’s apparently free for individual, non-commercial use with essentially no limits… for one year. After that, you have to pay $15 a month or $100 a year. Edit to add: Actually I think what happens is you have to renew every year, but you can do so as long as you continue to be non-commercial. I find the terms kind of unclear.
Even worse, EAGLE is no longer available on its own. Instead it’s included in a bloated beast of a package called Fusion 360, a more general collection of CAD tools, I guess — I haven’t looked into the non EAGLE part of it.
Here’s the good news: KiCad is freeware, it works well, and it imports EAGLE files. Here’s the bad news: It only imports EAGLE files from newer versions of the software, files written in XML format. Earlier versions of EAGLE wrote its files in proprietary binary formats which KiCad cannot import. The Mutable Instruments schematics and PCBs are in these binary formats.
I decided open source is pretty much bullshit if you can’t look at the files without a subscription to software you otherwise don’t even want. (And I certainly don’t otherwise want Fusion 360. There isn’t a Linux version, so I have it on my old Mac, where it runs like a constipated hippopotamus. Ugh.) So:
I made forks of several of the Mutable Instrument repositories:
For all but the first of these, the forked repositories are identical to the original except that I read all the .brd and .sch files into Fusion 360 and then exported them in EAGLE XML format. So they now can be imported by KiCad. And I added a sentence saying so to the README file. For the breadboard-friends repository I did that, but also added a folder containing KiCad versions of the projects, and I added a KiCad-only adaptation of bbf-eurojacks for Thonkiconn jacks.
Mutable has a bunch of other repositories but these looked like the five of most interest to me. If you’re a KiCad user, have a look.