Malbolge was invented by Ben Olmstead back in 1998. First Malbolge program was written in 2000, but it wasn't written by human - it was generated by a beam search algorithm implemented in Lisp.
Later, Lou Scheffer posted a few of his works regarding Malbolge and provided a
cat-like to copy its input to its output. He also mirrored the original interpreter and specification after the original site went down, and offered a general strategy of writing programs in Malbolge as well as some thoughts on its Turing-completeness.
Olmstead believed Malbolge to be a linear bounded automaton. There is a discussion about whether one can implement sensible loops in Malbolge, it took many years before the first non-terminating program was introduced.
Hisashi Iizawa proposed first "99 bottles of beer" application in 2005. He also proposed a guide for programming in Malbolge regarding it's usefulness software protection.