Please see my comment to the question. It's just that you would have some pages written in PHP and others in APS.NET. Nothing prevents them from cross-referencing each other, right? And your HTTP server should be configured to support both technologies. Is ASP.NET is supported, PHP won't be a problem. Refer to the documentation of your HTTP server.
From this question, I'm not sure if you really understand the role of Visual Studio or other IDE in development. Essentially, you only create files to be deployed (or built and then deployed). IDE only provides you assistance in writing file correctly. It does not build or deploy anything by itself. But one of the most important and valuable tools assisting with writing code is the debugger. This is where you have some more problems…
While ASP.NET is natively supported by Visual Studio which provides the ASP.NET-enabled "development server" and comprehensive debugging tools, it does not natively support PHP. It simply means that you have to find a different IDE to develop in PHP (which could be as simple as the text editor used to write PHP files), or you need to find some Visual Studio add-ons. Please see:
http://visualstudiogallery.msdn.microsoft.com/6eb51f05-ef01-4513-ac83-4c5f50c95fb5[
^],
http://php4vs.codeplex.com/[
^] (discontinued).
Some add-ons could be proprietary and commercial. You would to look at them by yourself:
http://bit.ly/16NoNMt[
^].
As to other IDEs, you could try PDT with Eclipse:
http://www.eclipse.org/pdt/downloads/[
^].
Another promising option would be Aptana Studio. Unfortunately, currently it only provides a PHP editor, but the debugger is said to be available soon, besides, reportedly, the debugging is already supported, via PDT or natively (please see the last link below), but I did not try it out. Please see:
http://www.aptana.com[
^],
http://www.aptana.com/products/php/[
^],
http://stackoverflow.com/questions/7102978/aptana-3-0-4-and-php-debugging[
^].
That all was about using "standard" PHP for HTTP. However, I used to use much more exotic option: PHP for ASP.NET. The product I used is called Phalanger:
http://en.wikipedia.org/wiki/Phalanger_%28compiler%29[
^],
http://www.php-compiler.net/[
^].
It compiles PHP into CLI assemblies and thus can be used in ASP.NET solution the same way as ASP.NET pages are used. It has a good Visual Studio integration, So, besides, I used this product to develop in "standard" PHP, just to be able to use the PHP debugger. I used common subset of the language and PHP libraries, developed separate fragments/modules and later moved them to the site which isn't ASP.NET-enabled. At that time, I could not find other ways to debug PHP code.
But, if you are already using ASP.NET-enabled server and also develop in PHP, Phalanger might turn out to make a perfect tool for you.
—SA
Submit an article or tip