To avoid the problems faced by the special character set of APL, J requires only the basic ASCII character set, resorting to the use of dot and colon characters to extend the meaning of the basic characters available.
J is a very terse and powerful language, and is often found to be useful for math programming, especially when performing operations on matrices. It also offers a flexible namespace scheme ("locales") which can be used as a framework for OOP.
Since J has no explicit print statement, the Hello World program would be simply:
"Hello world"