IBM/Rational ClearCase

Some developers believe ClearCase is the most wonderful SCM system ever, and certainly it is very powerful.

There is another school of thought, that CC is in fact a harsh and uncaring deity that sometimes destroys the work of mortal developers for its own mysterious reasons. Hence the belief that the best way of dealing with a serious CC problem is to have a virgin sacrifice a goat. Why the virgin? So you have an escalation policy to hand in case the goat sacrifice was not enough.

A point of note is that in order to set up the sacrifice you are likely to require around a week's worth of assistance from a CC consultant, at more than $1000 a day, much as you would with any other set up relating to CC.

[Serious point from another user]ClearCase is not CVS or [SubVersion] or even Perforce ... if you need a limited set of SCM capabilities (and let's face it sometimes developers do) then use one of these tools. However, if you want to protect your assets across an entire organisation or have some (reasonably) complex parallel development requirements, then you could make use of it...