It's an essay which most people in the Open Source Software World have read. Yet it's one that I've never got round to reading - that is, until tonight.
It's alot easier than I expected it to be. Non-technical people should have no worries in attempting to read it (though the motivation for doing so may be reduced by at least an order of magnitude). I'd thoroughly recommend it to anyone with 30 minutes free.
The best thing about it, for me, is that it's simple. It is in effect an empirical review of Linux's development through the eyes of the 'fetchmail' project.
For those of you new to ubuntu (reading this on planet.ubuntu-uk.org) - I'd thoroughly recommend reading it if you're a non-technical user. It's a nice explanation as to why the effort you're making in switching to Ubuntu is a step in the right direction.