STOD

STOD(STringmODifier), is an esoteric programming language, like brainfuck, but here all based on string modifing.

Hello, world!
"Hello, world!"#

Counts from 5 to 0
"5"[#@-]

Counts from user input to 0
?[#@-]

Quine
">++++++++++++++++++++++++++++++++++.<#>.<#">++++++++++++++++++++++++++++++++++.<#>.<#

Docs
All default brainfuck instructions and added this.

External resources

 * http://alc.comuf.com/STOD.php (Javascript interpreter)