RMS: "That is completely backwards. The free software movement is a political cause, not a technical one. 'Choose based on technical criteria first of all' is the opposite of what we say. [...] The GNU Project is not just a collection of software packages. Its intended result is a coherent operating system. It is particularly important therefore that GNU packages should work well with other GNU packages. For instance, we would like Emacs to work well with git or mercurial, but we especially want it to work well with Bzr..."