The IBM PC, XT, and AT came with a physical copy of the complete source code for the BIOS, several hundred pages in a 3-ring binder. (You can get a digital copy of it here: https://archive.org/download/bitsavers_ibmpcat150ferenceMar8... ) IBM did this, despite the fact that they strongly recommended applications use the BIOS interfaces and not access the hardware directly. They could've saved so much paper if they just documented the API, but they didn't --- they released the whole thing.

Yet 30 years later, in an era where it's easier than ever to distribute large amounts of information, companies regard such details as confidential and proprietary, hiding them even from their customers --- the real owners of their products. It costs next to nothing to distribute a DVD with each machine containing all the source code and documentation, or just put it up for download. Unfortunately the only recourse seems to be the occasional leak[1], and what's more disappointing is the overwhelming response that this is a "bad" and "insecure" thing, when it's really liberating what users should've received with their hardware.

[1] http://adamcaudill.com/2013/04/04/security-done-wrong-leaky-...