Creating SIM Application

Hi all,
Hope I'm not in a wrong channel..
I have a small project for my self to create an application on GSM SIM Card. Such an application will be portable because it is independent from handset. My problem is I'm really new to SIM application programming, even I never make an application for SIM Card.
If you have an idea how I start to work, what tool I can use, please give me an advise. I have my own mind that I should create and compile a program that has to be able to run under SIM card OS, then use a card reader/writer to plug my application in the sim card. But what kind of compiler and how do I download the compiled program to the card?

Thanks so much