Vim and Mercurial
Two plugins exists nowadays to interact with Mercurial within vim.
The hgcommand.vim plugin in the contrib directory of Mercurial,
The vcscommand plugin with its Mercurial backend.
The last one is likely to be more actively developed in a near future, and is described hereafter.
Vim VCS Mode and Mercurial
Bob Hiestand has developed a vim plugin useful for manipulating files controlled by CVS, SVN and SVK within VIM, including committing changes and performing diffs using the vimdiff system. A Mercurial (and sccs) backend were then provided by Vladimir Marek.
After installing the plugin and backend, you may use the following main mappings and commands :
:VCSCommit (<Leader>cc mapping)
:VCSAdd (<Leader>ca mapping)
:VCSVimDiff (<Leader>cv mapping)