I've been building web applications for about a decade now.  I started out with static HTML then moved to JavaScript and DHTML.  At this point, I got a job as a web developer and learned ASP.  With ASP, I wrote McAfee and Intuit's TurboTax tech support websites along with a series of other smaller websites.  I learned MySQL and became a database administrator.  ASP was run off of a Microsoft server using IIS, while MySQL was run from a Linux server.  During my time as a DBA, I learned basic Linux administration and enough Perl to write shell scripts to do administrative tasks like dumping databases and compressing them into a tar file.  I liked how Linux was so much more stable than Microsoft's ASP servers so I learned and fell in love with PHP.  This became my language of choice for many years and I built dozens of sites with it such as a popular photography communty called The Lens Flare.  I also dabbled in Java a little and wrote a web spider, chat room, and started building a multi-user game with it.

About 3 years ago, I learned Ruby on Rails because my boss read about it and thought it was cool. SInce then, I've programmed in both PHP and Ruby on Rails.  I tend to use PHP now for small simple projects and Rails for anything complicated.  This is because Rails code is easier to maintain once the project gets large and complex.