Imagine that there were one hundred Apache projects all using slightly different versions of the same source. Chaos would ensue.

Poor example. Apache is a healthy, growing project. The two other projects you mention sound like they are stale with developers who are unwilling to make changes and equally unwilling to allow someone else to step in. There's no reason to fork a healthy project, but stale projects are why Free Software license allow forking in the first place.

I do find the example of Apache kinda ironic--its orginal goal was to bring together the hundreds of patches made for the old NCSA server into a single project. So its really the reverse of your example.

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I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

Note: All code is untested, unless otherwise stated