Can anybody elucidate about why fork() is still used in Chromium or Node.js? They are not old-grown traditional forking Unix servers (unlike Apache or the mentioned databases in the paper). I would expect them to implement some of the alternatives and having fork() only as a fallback in the code (i.e. after a cascade of #ifdefs) if no other API is available. Therefore, I wonder where the fork() bottlenecks really appear in everyday's life.
Chrome on Windows uses CreateProcess, and Windows came first, so Chrome is mostly architected around an approach that would fit posix_spawn better. However, fork has some benefits that I went into here: