PHP is fine for web applications, but when it comes to software that scale, Java is the King. In my view Java shouldn't be used for small small to medium web applications. PHP might scale , but building a big system with many modules using a scripting language is a nightmare For somebody who has the time he should master both of them. Ruby on Rail is still new to be considered the next big thing.
Hmm... I'm probably interested with this... As I knew Borland Delphi was one of the best tool to create desktop apps. Does it gain popularity right now (Delphi for PHP)?
php Without any doubt , for big companies that can afford windows server and .Net .. (asp.net , c# - vb.net)
That's exactly it, but Ajax has been about for years and no one ever worried about it before, most things that Ajax is used for commonly can be done without using Ajax at all, IMO theres a massive difference between web applications and blogs, Ajax is supposed to ease the task of handling massive amounts of data client-side not for making contact forms.
It really comes down to what you know and are most comfortable with. They all have pros and cons. I use PHP for a majority of my projects, but I also use ASP.net and Java in more complex cases. If you're a new programmer, then I'd say PHP is the best because of the low learning curve, but if you've got experience in programming and have some larger-scale projects I'd move to ASP.net or Java.
Programming languages are a particular area of interest. Selecting a language involves many factors, and certainly isn't something that can be considered in a vacuum. Of course, it's important to pick something that can do the job correctly and efficiently, but depending on what you need to accomplish, and who you have to work with, the availability of external libraries, people to help you out, or even to hire you or be hired by you can all be important factors to weigh. so it is really difficult to say Which is the best ???