I must admit I haven't read every comment on this topic but I think that the initial question is just another dead-end question, like VI vs Emacs. The scope is reduced here to Mercurial vs Git, but why? There are so many more alternatives to these two tools, Bazaar, Veracity, Monotone, Fossil... Why not considering and arguing on these tools as well? The answer is very simple: nobody will never be able to make up an objective argumentation in favor of one of these tools (or at least an argumentation that everybody agree on). There will always be some people preferring one against the other, and giving very valid points in favor of it. I think this is just a choice that has to be done, and that can't be done in an objective way. In my opinion, the only thing that matters here, is not how hard it is to use the tool, because none of them are hard to use (seriously, it's just a matter of getting used to it) and because this will depend on individuals and how hard people try to understand how the tool works and what previous tools they were used to (coming from svn or from p4, etc...). The only thing that really matters is how easy it is for developers (old or potentially new to Boost) to find information, help or training about the tool, and how easy it integrates with any system. This is what tool popularity and marketshare reflects (2.300k results for "Git Version Control" vs 600k for "Mercurial Version Control" on Google). Regarding new developers, I would give my point of view as being part of this category: I'm not a Boost contributor, but I like to checkout open-source projects sources, and to build them from scratch. Having Boost running mercurial would certainly be a pain, because I don't have mercurial installed and I feel already tired of having to install another software to fetch Boost sources. For all open-source projects I'm following, none use mercurial, and more than half use Git, therefore I've got Git installed and I know how to use it (and I've got SVN for the other half). If Mercurial was more used/popular than Git, then I would have it instead of Git, and I would have learned to use it. It's not the case. My 2ยข. -- Beren Minor