I need to join the fray. Pat Eyler has announced a competition together with APress. The first installment is about how Rails has made me a better programmer. Details to be found here.
So, let's get at it. Rails has inspired and affected me in numerous ways. You got to realize that I have been programming web applications in Java for way too many years. Before that I've done both ASP and PHP. Nothing ever felt natural. I've tried many of the LISP frameworks (and Uncommon Web is really cool). I've embraced continuation-based frameworks. But none felt so powerful, yet nonintrusive. Rails embodies the best parts of Ruby.
For me, Rails is very interesting for several reasons. First and foremost is the fact that it is an incredibly good framework. It's really amazing how good it is. And that in itself acts as an inspiration. To know that software can be this good makes me want to strive to perfect my API's, make my libraries more usable, and finding new and novel ways to improve my DSL's.
But that's only part of it. The flip side of this is that Rails is not perfect. In fact, there are myriad ways it can be improved. And that gives me hope, because it also means that no matter how good my code gets, it can always get better. And that means I'll never be totally bored!
In a very literal sense, Rails has made me a better programmer in another way. Since Ruby on Rails was the first Ruby-application to make it into Karolinska Institutet, it means I can thank Rails for being able to write more Ruby at work. And writing Ruby instead of Java must make you a better programmer, neh?
Of course, Rails is an excellent testing tool for seeing how far we have left with JRuby. It goes without saying that you become a better programmer by implementing a language...
I have several applications and libraries that I keep in mind when writing my code. Those libraries act as a gauge against which I measure my code. Code quality, testing ability, interface, sheer trickyness; in all these areas, Rails is one of the top frameworks I know.