Category:No IO

Languages that perform no input or output.

(Note that this may be a somewhat contentious concept, for several reasons. It may mean that the language does not define any ways for a program to receive input or produce output. Or it may mean that the language requires that programs do not receive input or produce output. Or it may mean something else entirely. In other words - take this categorization with even more of a grain of salt than you take the rest of them.)