Every release is called by some word and a number. I don't know if there's a pattern to it. But for that particular release, it happened to be called Raisins, as far as I could tell.
_why (the author) is using it as a platform to write hacketyhack, a set of libraries and tutorials to help teach kids how to program, but letting them build blogs, downloaders, etc. in a couple lines.
Ubuntu calls its releases "Hardy Heron" and "Intrepid Ibex"
OGRE3D calls its releases "Eihort" and "Shoggoth"
I assume they're following the model of attaching a name to each official release.
To reply to the rest of your comment, I think it would be more exciting for beginners to learn how to program games. There is a much higher effort:reward ratio, though. You can't write Pong in 2 lines of code quite yet.
You could probably add a bit of readability by making the follow paragraph bullet points:
Compare... "This release adds a built-in manual, an error console, RubyGems integration, simple asynchronous downloads, an in-memory and database-backed image cache, support for external fonts, and, most prominently, its own unique library for packaging apps into little executables. OS X support is significantly better, as we switched from Carbon to Cocoa."
To...
"This release adds:
-A built-in manual
-An error console
-RubyGems integration
-Simple asynchronous downloads
-An in-memory and database-backed image cache
-Support for external fonts
-Most prominently, its own unique library for packaging apps into little executables
-OS X support is significantly better, as we switched from Carbon to Cocoa."
(Sorry if I mis-spaced it, I'm not sure where all the commas should go with my ultra-limited technical experience... but yes, bullets typically add a lot of readability in a paragraph with tons of things going on)
I'll add: I'm not sure how much of these are really simple for most hackers, the way "The U.S. flag is red, white, blue, rectangular, contains 13 stripes horizontal stripes, and 50 white stars on a blue background as a separate rectangle in the top-left corner" is simple for an American - but as someone far more business-inclined than technologically inclined, I can piece together 90% of the changes when reading in bullets, whereas the paragraph is overwhelming. If it's all super-simple things for a decently skilled hacker, then never mind the input and congrats on the new release :)
This just makes me chuckle. Apparently you have not seen _Why's other docs, particularly the epic entitled Nobody Knows Shoes.
You're lucky (and I, who have different tastes, am unlucky) that the list wasn't delivered as a napkin scrawl that could only be read by printing it out and folding it into a Moebius strip. Or as an illuminated epic poem. Or in musical form.
_why is one of the most amazing, creative hackers out there. I get the sense that his goal isn't to take over the planet with Shoes, but he'd rather get Ruby programming into as many hands as possible.
Who does it alienate? Certainly not the mainstream. I've linked his (poignant) guide to friends who aren't big programming types, and they all fell in love with it. Isn't that the more important audience as it is? The people who want to fall in love with programming but haven't yet?
Hmm. That's a shame. It's well-written, easy to follow, and teaches well. I'll never understand the programming mentality that says hard is better just because it excludes people.