We currently use kiln which uses mercurial under the bonnet as our source/version control system. However we are looking to migrate into something that is a quite similar i.e mercurial based and one that can be on a hosted server on site.
I came across bitbucket server as an alternative.
I'd like to learn more about this in order to make a decision and i'm guessing that others would have some first hand experience on best ways to approach migration.