Yo!

I heard you like esoteric programming languages.

Here's one for you: yo!lang.
yo!lang is a brainfuck dialect, having only 8 commands operating on an instruction and a data pointer.

Adapted from the Wikipedia article on brainfuck:

yo increment the data pointer (to point to the next cell to the right).
YO decrement the data pointer (to point to the next cell to the left).
Yo! increment (increase by one) the byte at the data pointer.
Yo? decrement (decrease by one) the byte at the data pointer.
YO! output the byte at the data pointer.
yo? accept one byte of input, storing its value in the byte at the data pointer.
yo! if the byte at the data pointer is zero, then instead of moving the instruction pointer forward
to the next command, jump it forward to the command after the matching YO? command.
YO? if the byte at the data pointer is nonzero, then instead of moving the instruction pointer forward
to the next command, jump it back to the command after the matching yo! command.