PT Malbolge is a programming language that is designed to be impossible to program in. The name comes from Dante's eighth circle of hell where the practitioners of deception are cast. The runtime interpreter uses trinary and places code and data in the same memory space. When the program is run, each program value is read and decoded using the previous program value. The language is believed to be Turing complete.
There are currently only two Malbolge programs written. The first is trivial as well as useless and the other is the usual "hello world". The latter was developed using a genetic algorithm and isn't perfect.
Nop
DP
Hello World
(=<`$9]7<5YXz7wT.3,+O/o'K%$H"'~D|#z@b=`{^Lx8%$Xmrkpohm-kNi;gsedcba`_^]\[ZYXWVUTS
RQPONMLKJIHGFEDCBA@?>=<;:9876543s+O<oLmMSW says, "Cool, trinary!" :) We should write a tcl compiler for it, just to bug the Malbolge developers...