git was, for me, final proof of the `release early, release often' idea.
The initial git was very nearly unusable by mortals and was certainly far
too disk-space-inefficient to actually be used for a project with a churn
rate as high as the kernel for long.
But because the *representation* was right, the other problems could be
solved later (and were, yet fast enough that nobody's disks filled up):
and a whole bunch of really nasty ones that had bedeviled other VC systems
for ages just ceased to exist, like rename tracking (what? you need to
track renames? why not just search for similar content when you pack? that
way you can merge stuff that's similar whether or not it originated in a
And it keeps improving. My kernel git repo actually uses *less* space now
than it did in the 2.6.18 era because of repacker improvements...