Microsoft ASP.NET Vs. PHP and LAMP
PHP is a very popular HTML-embedded scripting language designed for rapid web development. The syntax is similar to C and Java. PHP is relatively mature, has complete online documentation, and has a very active online community.
PHP 4 and 5 are more efficient and faster than ASP.NET due to less overhead and less platform code to execute. ASP.NET pages compile, as opposed to running directly as scripts, but are on top of a large run-time environment. As with the rest of .NET the developer is forced to use an object oriented design, creating extra code for simple applications. With PHP object oriented development is optional and new OO features are added with each major release.
PHP is free and available for Windows, Unix, and Linux with the Apache and IIS web servers (and possibly others). Microsoft's ASP.NET is free, but has the platform costs of Windows and security weakness of IIS. PHP is also [open source], bringing many other benefits. Combined with other open source software, the Linux-Apache-My SQL-PHP (LAMP) platform is a very scalable and flexible system on par or better than .NET for most situations.
PHP vs ASP.NET - which is better ?
PHP would be my answer. There are a number of reasons why, so here:
PHP vs ASP vs Java vs Flash vs Cold Fusion
PHP's main advantage is that it is FREE, and free is good. PHP supports all platforms, and can be installed on any platform that being windows, Linux, mac, UNIX, BSD, sun OS and every server unlike ASP and flash. PHP does not have to be compiled, unlike ASP, Java, and Flash you can at any time change any part of your code in a matter of opening the file in a text editor(any), modifying it and saving your changes and your code and page is updated.
Lets go through the process that you have to go trough with ASP, find a computer with asp compiler, find your code file, modify it, compile it and then put it on the server overwriting the previous file.
ASP.net is junk, in fact all .net based programming languages are (except maybe for VB.net which the entire .net thing was made for), you cant run the programs compiled in .net unless you have a .net platform installed on your computer, as to web pages, as freethinker said you can't view them in Mozilla, Opera or any older version of Netscape.
The problem with flash seems to be in that anybody that does not have flash player installed on their computer can not view your website, hence you loose potential viewers.
Cold Fusion Lacks standard and security. Java is great, but it is a hard language to learn, and there is nothing you can do in java, that you cant do in PHP which is not as strict on its syntax. People when speaking of java seem to talk a lot about applet programming and script, Java and JavaScript are two totally, and entirely different programming languages who's only similarity is in syntax. Main difference being Javascript is a client side programming language and Java is a server side one, big, big difference.
JS's is a client side scripting language and it serves a different purpose than PHP, client side means all your code is visible, + if you use a browser that does not support JS, you cant see any contents; so browsers like Opera and X Web are automatically out and if I go into my IE options or Netscape options I can always turn JS off, because you can use JS to automatically download a virus onto your system. Java is a totally different story, I wont discuss it here, but it is one of those languages that comes close to PHP, and differs only in speed;PHP is faster and more efficient.
So PHP vs. ASP:
________________PHP4________PHP5__________ ASP
Software Price ____ free ________free __________ free
Platform Price _____ free _______ free ___________ $
Speed ___________ fast _______ fast __________ slow
Efficiency ________ very _______ very ________ not efficient
Resources Needed_ few _______ few __________ lots
Security _________ secure ____ secure _______ secure
Platform __________ all ________ all ______ win32 IIS mainly and Apache recently
Open Source _____ yes _______ yes ___________ no
exception handling _ no _________ yes __________ yes
OOP support ____ not strong ____ full ___________ full
Another thing that you might consider is Database, and PHP's uniqueness is also in that PHP is almost a part of a database server, if in other languages Database support is written in add on functions “dll files”, PHP's is written in the engine itself, Database almost feels like PHP is a part of it, and thus the speed of their communication is a lot higher than that of ASP and MsSQL's and Oracle and Java's.