[isabelle-dev] Isabelle history via Mercurial

[Makarius]

As the result of some experiments with Mercurial, which is one 
representative of the upcoming generation of "distributed" version control 
systems, the Isabelle history is now available online:

  http://isabelle.in.tum.de/isabelle-bin/mercurial.cgi

The web interface allows to browse conveniently through 15 years of 
recorded history: the CVS era starts at Thu Sep 16 12:20:38 1993, see the 
large (!) changeset 0 (hash key a5a9c433f639).

Some pre-historical records of Isabelle development are also available:

  http://isabelle.in.tum.de/isabelle-bin/mercurial.cgi/file/a5a9c433f639/edits.txt


Right now the underlying data is retrieved from the official CVS 
repository every other hour. This means the website can be already be used 
seriously, to query the history, or subscribe to changes via the rss/atom 
feed, or just learn how to use Mercurial.  Over time we will see if it is 
feasible to convert the actual repository at some point.

See http://www.selenic.com/mercurial/wiki/ for more information on the 
"hg" client of Mercurial.  The quick start is as follows:

  hg clone http://isabelle.in.tum.de/isabelle-bin/mercurial.cgi isabelle-hg

This will produce a self-contained clone of the online repository (150MB 
of disk space).  An adhoc web service can then be spawned like this:

  cd isabelle-hg; hg serve -v

Now you can browse through this locally, using Firefox etc.

Updates from the original version can be "pulled" later, see the fine 
Mercurial manuals.


A general introduction to distributed version control is given here: 

  http://betterexplained.com/articles/intro-to-distributed-version-control-illustrated/ 

The nice thing is that well-engineered systems like Mercurial and Bazaar 
are actually easier to use than CVS or SVN, which have accumulated a lot 
of legacy features over time.  Only the better-known git by Torvalds is a 
bit more cryptic, being targeted at kernel hackers, but his Google talk is 
quite interesting nonetheless.


	Makarius