McVoy on BitKeeper, Linus, and Perens
Joe Barr writes "The story of how BitKeeper has come to be Linus Torvalds' (and many other kernel hackers) tool of choice in maintaining the Linux development tree is worthy of a book. Here's the Cliff Note's version of McVoy's contribution to Linux kernel development, BitKeeper, and countless hours of flaming on the role of open source and proprietary software."
BitKeeper, otoh, sells software. If they Open Sourced it, they'd loose a lot (most) of the sales of their ownly product.
Different companies, different products, different focus.
bitkeeper uses SCCS as its underlying layer, sort of similar to how CVS uses RCS for the files. There are (free) SCCS tools available, so you can probably pull your code out of bk if you feel the urge. Also, as I understand it, if the company ever dies, bk goes open source. Not so proprietary now, is it?
bk's a great solution to a problem not really addressed by anyone else. Personally, I hope it doesn't go away.
I don't use it, by the way. I'm thinking of writing a webdav client for a non-Unix operating system, and extending it to support subversion. The bk freebie license prevents me from using bk while working on a competing product.