The last assertion made in that answer is unfounded and false -
"Even if the entire OS code was made public tomorrow morning, it would take years before someone figures out how to build it, the complexity of the build system itself is mind boggling."
is contradicted by the fact that just recently a version of windows source (old, but still) was leaked, and people did manage to successfully build and boot the leaked windows (xp and server 2003 IIRC) code within days of that source becoming available.
is contradicted by the fact that just recently a version of windows source (old, but still) was leaked, and people did manage to successfully build and boot the leaked windows (xp and server 2003 IIRC) code within days of that source becoming available.