Version Control Software

[Roy Smith]

In article <vg3obb899rk.fsf at coffee.modeemi.fi>, Anssi Saari <as at sci.fi> 
wrote:

> I have some experience with ClearCase. I don't know why anyone would buy
> it since it's bloated and slow and hard to use and likes to take over
> your computer.

ClearCase was the right solution to certain specific problems which 
existed 20 years ago.  It does have a couple of cool features.

1) Every revision of every file exists simultaneously in the file system 
namespace (CC exports its repo as a quasi-NFS file system).  That means 
you can look at every revision with all your normal command-line tools 
(diff, grep, whatever).

2) It ships with an integrated build tool which can automatically learn 
your dependency graph.  This is paired with a feature called "winking 
in".  Let's say I'm building a humungous C++ project which takes hours 
to compile.  And I'm part of a team of 50 developers, all working on the 
same code.

If I need foo.o, and some other developer has already compiled a foo.o 
with exactly the same dependency graph (including what versions of the 
toolchain and option flags), I just instantly and transparently get a 
copy of their file instead of having to build it myself.  This can 
potentially save a huge amount of build time. 

All that being said, it is, as Anssi points out, a horrible, bloated, 
overpriced, complicated mess which requires teams of specially trained 
ClearCase admins to run.  In other words, it's exactly the sort of thing 
big, stupid, Fortune-500 companies buy because the IBM salesperson plays 
golf with the CIO.