+
+#### Another possible approach
+
+Here's what I (tuomov) think, would be a “cleaner” approach:
+
+ 1. Upon starting to edit, Ikiwiki gets a copy of the page, and `darcs changes --context`.
+ This context _and_ the present version of the page are stored in as the “version” of the
+ page in a hidden control of the HTML.
+ Thus the HTML includes all that is needed to generate a patch wrt. to the state of the
+ repository at the time the edit was started. This is of course all that darcs needs.
+ 2. Once the user is done with editing, _Ikiwiki generates a patch bundle_ for darcs.
+ This should be easy with existing `Text::Diff` or somesuch modules, as the Web edits
+ only concern single files. The reason why the old version of the page is stored in
+ the HTML (possibly compressed) is that the diff can be generated.
+ 3. Now this patch bundle is applied with `darcs apply`, or sent by email for moderation…
+ there are many possibilities.
+
+This approach avoids some of the problems of concurrent edits that the previous one may have,
+although there may be conflicts, which may or may not propagate to the displayed web page.
+(Unfortunately there is not an option to `darcs apply` to generate some sort of ‘confliction resolution
+bundle’.) Also, only one repository is needed, as it is never directly modified
+by Ikiwiki.
+
+This approach might be applicable to other distributed VCSs as well, although they're not as oriented
+towards transmitting changes with standalone patch bundles (often by email) as darcs is.
+
+## [[Git]]
+
+Regarding the Git support, Recai says:
+
+I have been testing it for the past few days and it seems satisfactory. I
+haven't observed any race condition regarding the concurrent blog commits
+and it handles merge conflicts gracefully as far as I can see.
+
+As you may notice from the patch size, GIT support is not so trivial to
+implement (for me, at least). Being a fairly fresh code base it has some
+bugs. It also has some drawbacks (especially wrt merge which was the hard
+part). GIT doesn't have a similar functionality like 'svn merge -rOLD:NEW
+FILE' (please see the relevant comment in mergepast for more details), so I
+had to invent an ugly hack just for the purpose.
+
+By design, Git backend uses a "master-clone" repository pair approach in contrast
+to the single repository approach (here, _clone_ may be considered as the working
+copy of a fictious web user). Even though a single repository implementation is
+possible, it somewhat increases the code complexity of backend (I couldn't figure
+out a uniform method which doesn't depend on the prefered repository model, yet).
+By exploiting the fact that the master repo and _web user_'s repo (`srcdir`) are all
+on the same local machine, I suggest to create the latter with the "`git clone -l -s`"
+command to save disk space.
+
+Note that, as a rule of thumb, you should always put the rcs wrapper (`post-update`)
+into the master repository (`.git/hooks/`) as can be noticed in the Git wrappers of
+the sample [[ikiwiki.setup]].
+
+## [[Mercurial]]
+
+The Mercurial backend is still in a early phase, so it may not be mature
+enough, but it should be simple to understand and use.
+
+As Mercurial is a distributed RCS, it lacks the distinction between
+repository and working copy (every wc is a repo).
+
+This means that the Mercurial backend uses directly the repository as
+working copy (the master M and the working copy W described in the svn
+example are the same thing).
+
+You only need to specify 'srcdir' (the repository M) and 'destdir' (where
+the HTML will be generated).
+
+Master repository M.
+
+RCS commit from the outside are installed into M.
+
+M is directly used as working copy (M is also W).
+
+HTML is generated from the working copy in M. rcs_update() will update
+to the last committed revision in M (the same as 'hg update').
+If you use an 'update' hook you can generate automatically the HTML
+in the destination directory each time 'hg update' is called.
+
+CGI operates on M. rcs_commit() will commit directly in M.
+
+If you have any question or suggestion about the Mercurial backend
+please refer to [Emanuele](http://nerd.ocracy.org/em/)
+
+## [[tla]]
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