The debate whether PHP or ASP.net is the better programming language rages on, with both camps firmly embedded in their opinions. Here is a simple comparison of the two rivals to help make up your own mind.
User Friendliness - Originally written in C programming language as a replacement for a set of Perl scripts, PHP is simpler to use than the relatively new ASP.net. A lack of updates and language tools can, however, make PHP a little cumbersome - although (in spite of minimal language tools) it performs its tasks well. Though harder to learn, ASP.net, on the other hand, offers more options when it comes to usable languages, which include, for instance, C++, C#, J# and VB.net.
MySQL Support - Both languages support MySQL, but PHP is without a doubt the better option when it comes to supporting this database management system, which is why PHP is used with MySQL by both WordPress and Wikipedia. PHP is also said to provide better embedded support for SQLite.
OOP Support - Object oriented programming is equally well supported by PHP, with ASP.net also providing capable support.
Snags and Fixes - PHP, as an open source product, enjoys free worldwide support, meaning there are rarely any snags and, if fixes are required, they are usually implemented more or less instantly. ASP.net is owned and supported by Microsoft, meaning fixes take time as they have to follow support queries.
These differences are just a fraction of the overall picture. More detailed information can be found at the WHIR.