Scope of the Open Source Programming language-PHP

Hello all

I would like to know what people at cnet think about PHP because I have been hearing about the pros and cons of PHP since lately.

Do all big companies rely more on Dot Net and Java? Is PHP for small companies only? If possible, do mention names of few companies working on PHP projects-either the software companies or their clients.

Does PHP has more functionality than others?

Is PHP less reliable in terms of security than Dot Net or Java?

All readers are welcome to post their opinions.

Thanks