 <p>Both are suitable for bigger projects and both are secure too. But these two things depends on the Programmer or Team you hire. You can have a look <a href="http://en.wikipedia.org/wiki/Programming_languages_used_in_most_popular_websites" rel="nofollow">here</a>.</p> <p>ASP is fully Object oriented and can be written only in OOPS Concept. PHP Can be written in Object oriented as well as Procedural ways. PHP was a Procedural language when it is implemented first but later gained OOPS Principles. Thats why.</p> <p>PHP is an open source language. It is free to the community and lots of tutorials and examples are available everywhere. ASP.net is free framework but Web server and OS Costs.</p>