The main objection against Ruby on Rails it’s about its performances, especially when they are compared to PHP. Although it’s cheaper to add up new computational power (or lease it from services like Amazon EC2) than pay for more developers, this objection has some real reason. Ruby 1.8.x is not really fast, and this is a problem for every framework built on top of it as RoR, but things are changing, as this benchmarks from Antonio Cangiano shows:
- Ruby 1.9 is 2-3 times faster than Ruby 1.8.6;
- JRuby is now as fast as Ruby 1.8.6, so you can now get all the power of Ruby on a Java application server;
- There’s a lot of room for improvements, as some other projects (XRuby, Rubinius) indicate.