Why would I want to use this over git or mercurial?
You wouldn't, unless you have very specific niche needs. They're pretty upfront about it: >Why use BitKeeper when there are lots of great alternatives? >For many projects, the answer is: you shouldn’t. https://www.bitkeeper.org/why.html
BitKeeper itself is a collection of repositories. Download an install image, install, and clone it:
$ bk clone http://bkbits.net/u/bk/bugfix
$ cd bugfix
$ bk here
PRODUCT
default
$ bk comps -m
./src/gui/tcltk/bwidget
./src/gui/tcltk/tcl
./src/gui/tcltk/tk
./src/gui/tcltk/tkcon
./src/gui/tcltk/tktable
./src/gui/tcltk/tktreectrl
./src/win32/dll/scc
./src/win32/dll/shellx
./src/win32/dll/shellx/src
./src/win32/msys
./src/win32/vss2bk
which shows that what we clone by default doesn't include all that other crud (we cache the build result from that and populate it as needed to do builds).Play with it, it's very different from Git, the subrepo binding is just like file bindings. Everything works together and obeys the same timeline.