J Programming Language is an Functional-Level Programming (also known as higher-order functional programming). It is used for mathematical and statistical programming generally used for operation on matrices. It is also used in Network Performance Analysis and Extreme Programming. J programming is Open Source Language and works on window, Mac and Linux.
J Programming permits point-free-style and function composition. It is considered to be difficult to read by some programmers. The hello world program in J is Example of Program in UNIX System:
#!/bin/jc echo 'Hello, world!' exit ''
Good programming tutorial on J Language can be access using following Books: