NodeJS was forked into io.js, which continued ahead onto 2.0 and 3.0. Now the two projects are merging back and they are continuing with io.js version numbering

NodeJS was forked into io.js, which continued ahead onto 2.0 and 3.0. Now the two projects are merging back and they are continuing with io.js version numbering rather than Node's, starting with version 4.0 today.