A majority of my web development experience has been on the .Net stack (mainly Asp.net C#). I am looking to learn something new in my spare time, for the use of personal projects and possibly for use professionally (as an ISV). I know some Python, done some scripting with it in the past, nothing on the web though. Php has been around for a long time and RoR has gained a lot of popularity. Are there any developers from the .NET world that have migrated over to one or more of the other platforms? If so, which do you prefer and why? Which would you suggest and why?