With all the disagreement over the past few days, it might seem like Merb and Rails are worlds apart. But David's latest post demonstrates what I've been saying all along: we're more alike than different.
In the latest installment, he takes on the myth that "Rails is hard because of Ruby". Effectively, a bunch of people are comfortable in their language of choice (PHP, Java, Perl) and prefer to switch over to an MVC clone in their language of choice than learn the big bad scary Ruby.
As David succinctly argued, Ruby is just not that hard a language to learn. It's better organized than PHP (with its absurdly large global namespace) and less ceremonious than Java (no IStrategyBuilderFactories here).
And what's fantastic about Ruby is how quickly and simply new programmers are exposed to advanced concepts like lambdas. Because iteration is accomplished in Ruby almost exclusively with blocks, it's near impossible to spend even a day in Ruby without learning what blocks are. Spend a little more time with Ruby, and the power of the closures that come along with lambdas becomes obvious. All without the need for an extensive study of the CS benefits of the construct.
Ruby is so easy, in fact, that the slim Learn to Program tome is written using Ruby as a base. It's so straight forward that my wife, who's hardly a programmer, was writing a program to count down "99 bottles of beer on the wall" within a few hours of picking up the book (and was even embellishing the program with a few interactive touches :-D )
Finally, implicit in the "I don't want Rails because it's Ruby" claim is the oft-heard myth that Ruby is slow. As I explained in my keynote at MerbCamp, Ruby does very well even compared with raw PHP. But when you compare Ruby frameworks (even Rails) against CakePHP, Rails destroys the competition. And Merb does even better. That's because PHP's fundamental architecture does not play very well with large frameworks, while Ruby deployment options can manage a fairly large framework with very small runtime impact.
What I showed at MerbCamp was that it was possible to squeeze up to 4,000 requests per second through the Merb stack, or around 1,500 requests per second when going through a controller and template, but that frameworks like CakePHP got only about 100 requests per second, even with a code accelerator.
Bottom line: don't let anyone tell you that Ruby web applications need be slow. The language itself is certainly slow, but I don't see a ton of Fibonacci web applications being built, so the real question is about where the bottlenecks are, and Ruby acquits itself very well.