Ruby on Rails
Today, I finally took a look at it.
It seems cool. A REST-ful framework for creating dynamic web applications with minimal amounts of coding. Writing REST-ful applications with clean URLs in other frameworks can be a big, big pain (just try doing this with plain vanilla servlets -- you will be begging for mercy).
Beyond that, what I like about it is that it is an entire stack, integrated together very nicely. This is something I've really found lacking with Python. Python has a million web frameworks, but none of them have the whole package like Rails does.
I've considered using Python for some side projects, and I still haven't found "the one" Python web framework. Do I use mod_python or FastCGI? Which Object-Relational mapper is the best? What templating language should I use? Which view framework will give me beautiful, search engine friendly, professional-looking URLs? Finally, of these miriad frameworks, which of them can I count on an active and outward-facing developer community for good documentation and support?
It's a friggin' hassle.
The same problem applies in the Java world, but there you can always muddle through with the standard Servlet/JSP package, which has institutional support from Sun, or go for one of the frameworks like Struts, Spring, and Hibernate that have thousands of developers, good docs, books published, etc.
But in the end...is Rails worth learning Ruby over? Hmmm...
Update: Here's some links of commentary from the Python community.
Titus (who I believe is a/the Quixote developer): Rails:Ruby :: Zope:Python (just five years later).
Ryan Tomayko: No Rails for Python?
Neil Blakey-Milner: More Web Framework Wars.