Programming language for a website

What do you mean by "strongest"?

I freely admit to being totally biased, but I'd say PHP. It's free, very popular, well supported, flexible and easy to learn.

I found ASP to be really similar, but prefer working on unix boxes myself. Personally I dfind JSP to be a PITA, but that could just be because I have not used it enough to get very familiar with it. Haven't used dot net at all.

I'm sure it is all horses for courses, but PHP is a pretty good all round solution. If you are just starting out with PHP I'd make sure that you are using PHP 5 from the outset so that you don't have to "unlearn" stuff later on.

I would second Shirthead's opinion of PHP (especially version 5).

However... I hate blanket statements. While PHP is my favorite tool, my answer would vary based on what you are looking for in a language. If you're just poking around, coding a personal site, looking for a skillset to market as a contractor, etc. Then PHP will server you well.

If you are looking to beef up your resume in the hopes of landing a corporate job. Then I would recommend turning to the 'dark side' and learn the ways of the evil 'M'-pire. That is to say, learn .NET.

BTW, I haven't touched ASP since I left my corporate job. And I haven't looked back (at ASP, I liked working for a stable company).

Something to consider is the context you're operating in too. For example, is the language's popularity an important factor, in terms of server support, or do you control the server so as to choose a better language? Or, how much initial cost (time as well) are you willing to incur, as you learn the language, or hire a programmer? Etc.

Because of the constraints I personally face, I've been able to experiment a little with a few languages that are relatively unpopular for web programming, such as Common Lisp, Python and Ruby. They have been quite good -- enough that I'm convinced to drop PHP in favour of one of them for my next project if viable.