I did a project on integrating Mercurial with Mongo before, and I have to say being a Python developer I didn&#x27;t have too much difficulty in figuring the right API, although the documentation is not so great. The code itself uses a lot of abbreviations which you have to really be patient to get familiar. The Mercurial model [1] is a pleasant read for a couple train ride (read it a few times I encourage). Others have done amazing things with hg too, like making hg available in Javascript (now an abandon project).<p>Mercurial is actually very easy to use. However, it didn&#x27;t have the exact lightweight concept of git branch until they implemented bookmark a few years ago. I don&#x27;t remember the limitation of bookmarks now it has been a few years since I used Mercurial...<p>I too thank Matt and core developers working on Mercurial. One thing I feel Matt and developers need to address is hosting hg on PyPI infrastructure instead of redirecting to their own server. From time to time the server wouldn&#x27;t deliver anything and it was frustrating to see our builds fail (of course some say you should have cached the build and not hitting Mercurial server every day).<p>[1]: <a href="https:&#x2F;&#x2F;www.mercurial-scm.org&#x2F;wiki&#x2F;Presentations?action=AttachFile&amp;do=get&amp;target=ols-mercurial-paper.pdf" rel="nofollow">https:&#x2F;&#x2F;www.mercurial-scm.org&#x2F;wiki&#x2F;Presentations?action=Atta...</a>