Well... I believe that there is definate proven truth to the fact that scripting languages are just as useful as compiled - however I'd argue that compiled makes more sense.

With virtualization, risc processor technology, multicore systems, and everyone wanting faster and faster performance (and not usually getting it due to software bloat or whatever) ...

It seems to me - lean and mean processor command sets would make actual "processors" really shine! Think about it: If you want virtualization and have a fairly small command set on a processor, and that processor hosting an operating system that then can run "Virtual Machines" on it in such a way that the binary code in the virtual machine can be made to literally execute natively on the host processor - WOW - that would be some VERY SLICK utilization of current technology if you ask me.

Now... instead, the scripting trends, compile on demand, blah blah... trends turn this same scenario into a text parsing nightmare, waste of CPU time, and don't get me started on the the whole XML "revolution".

Sure... they say with todays fast computers you don't need to have tight code... or compiled code... so our collective advancements are - bloated code, more IP exposure risks, faster machines with 4 CPU's run as fast as a 386 with Windows for Work Groups ....

Sure... Compiled versus Scripted might not matter to you... I think we all suffer one way or another. Like everything these days, more products, faster turn around... less quality.. all to get it out there faster and get paid. Hmm.

--Jason

I would not use a weakly typed or fully interpreted language (e.g. PHP) for a large project. Compilers and type checking find a lot of bugs before the code is even run. Likewise, I would not write a batch file to copy a dozen files in C#, and interpreted langauages are great for quick 'n dirty programs that you write in 10 minutes, use and then forget about. For example, I analyse my web server log files using AWK.

In the end, it's horses for courses. Always has been, always will be.

I wouldn't tell anyone to take his favorite pick from any scripting or 'regular' language for any application. Instead I would tell him to consider th 'big picture', i. e. who is going to use this application, in terms of number of users, possibly concurrently, and maybe including other applications! Also it is important to see where the application is going to run, and what the rstrictions on this machine are, what other applications it is competing with for ressources, etc..

When you look at a single-user application that is strongly interactive, then just about anyone would tell you: response time is not an issue, use a dynamic language - because it is fast to write and test. But if that application is linked to some kind of online service, together with thousands of like applications at the same time, suddenly there may be a bottleneck at this other interface: The online server will set up a ommunication with your application and it's own responsiveness will be tied to how fast your own application can react, on top of the load the other applications put on it. And here is where it still might be better to use a compiled language.

So, this is my Checklist:
1. Look at the interfaces. If there's just one interface that might connect to another application, then don't use scripting.
2. Look at concurrency. If you don't have any handle on the uppermost limit of users that might use your application at the same time on the same machine, then don't use scripting.
3. Look at ressources. If your application might run on machines that tend to run lots of other applications as well, and who it needs to compete for ressources with, then don't use scripting.

I might be overcautios. But if you ignore any of the above, you run the risk of clogging down a machine. Maybe not your's, maybe not any of your friends'. But quite possibly someone's.

What about PHP vs JSP? Seems like this is getting decided more and more everyday. What compile and deploy, when you can just deploy.

Isn't facebook run on PHP?