.NET is ideal for rapid web development. If you are running on a windows platform, its infinitely more scalable than php. PHP's OOP model is still in it's infancy, which greatly decreases the performance of PHP when using objects and defining custom classes. The only problem again is if you aren't running an IIS solution. .NET emulation on a linux platform is a nightmare and a half, and the same goes for Apache on Windows. I think PHP allows you to break too many of the "rules" of a robust language because it is not as strongly typed. If you want to talk about a language in a heterogenous environement, Java is the way to go!