I advise all to read it:
Hidden Windows API a.k.a. Native API
What was most interesting part for me:
Real Gurus Come Back
- One other effect might come about. Real Gurus might re-emerge.
Before the rise of the mass-market computer, Unix and freeware operating systems, every hardware vendor provided their own operating system. These systems nearly always had weird little undocumented features and commands. People who worked or previosly worked for for a particular vendor often possessed knowledge of the that vendor's operating system and hardware that others did not. They were real Gurus. Currently, one can become a Guru for a freeware OS by merely working hard. Studying and hacking on the source code suffices to become a freeware OS Guru. By nature of their source code distributions, the freeware OSes possess no deliberately hidden knowledge, although some knowledge may seem obscure due to poor or non-existant documentation.
In combination with the "favored vendor" effect, a hidden API could mean that some select few will become Real Gurus, possessors of secret knowledge. Those insiders will end up fulfilling a role similar the Masters of old-time Guilds. They will govern who enters the inner circle, who gets to know and use the secret knowledge. We could end up in a state similar to that of the medieval Guild systems: fractured, incomplete knowledge jealously guarded by a select few causing a general stagnation and lack of innovation.