JavaCard OS

As titled, How to start my first hello world applet in java card? What needs to be prepared?

You can view this topic https://javacardos.com/javacardforum/viewforum.php?f=31 to learn Applets Development.

To learn Java Card, first of all you must need to learn Java Card related Specification,such as Java Card Runtime Environment Specification, Java Card Virtual Machine Specification and so on.