I have been using the GCC Compiler for months, which is great, and works very well. But I wonder which C++ Compiler do big/medium enterprises use for high optimizations/performance in Linux (x86, PowerPC...).

It may seem a very stupid question, but I havent found the answer anywhere.

As far as I know, the best PowerPC Compiler is the XL, but x86 I dont know anything.

EDIT: Thanks a lot for all the answers. They were all very helpful. You have convinced me to use GCC ;) Regards!

In the places I have worked we have always used gcc, even for embedded applications/software.

Performance improvements are much more likely to come from your code rather than your compiler choice anyway!

I'm developing a iOS based enterprise app. The client is going to install the app on their employees' personal iPhones. So while an employee leaves the company, the company would have a very strong desire to delete the app on his/her iPhone.

We are going to buy the $299 enterprise license and we have that employee's UDID. I thought I saw somewhere that we can make it by making changes to the mobile provision, but I can'd find it out.

So any ideals?

Update I found this in Apple's Enterprise Deployment Guide page 66:

"Disabling an Enterprise Application

If you need to disable an in-house application, you can do so by revoking the identity used to sign the distribution provisioning profile. The application will no longer be able to be installed, and if it’s already installed, it will no longer open."

I believe that means I can disable the app on every device by revoking the com.companyname.productname thing, but I found no info in the file about how to disable some certain user.

What I would suggest is to make the user enter his id-number (social-security number or something in USA) and then every time the app opens, query an online database with all the user's id's etc. (Automatically/behind the scenes) As soon as he left the company, remove him from the DB. The app will then only go to a static page and do nothing (maybe display a company logo). This way the app becomes unusable after you remove him from your online database.

Regarding physically deleting the app of his phone, I have no idea if that could be done or will be allowed. If you could delete the app from within itself, then it would also need to query a database.