[ConfucianNardin]

VS2017 opens the correct documentation most of the time, and in the default web browser.

For C++, cppreference provides archives of all their docs: http://en.cppreference.com/w/Cppreference:Archives.

Of course, that won't help you for Win32 or .NET.

There's also https://zealdocs.org/

[lorenzhs]

There's also https://github.com/jeaye/stdman which provides the pages from cppreference as manpages, and https://github.com/aitjcize/cppman (which I haven't used, but seems to look a bit nicer)