As in, what does that mean, anyway? I'll try and keep it short.
When I spoke of Ruby on Rails the other day as the 'hotsh!t dev platform of the day', I realized that it would need some clarification. So let me clarify.
Coding pretty much anything is a massive, time consuming job. That's part of the reason that computer languages have evolved from 1s and 0s to Fortran to C to C++ to Java to Ruby: if you were to try and write the Twitter website in assembly language (binary), you'd be there coding for a very long time. If you were to try and write Windows 7, you couldn't do it.