I've written the following programs in Malbolge:
I've written some programming tools for Malbolge, too:
Some general information about Malbolge can be found at Esolang.
With this program, you can generate Malbolge programs which simply print out a text message. The desired text can be committed as a command line argument or via STDIN. Not supported characters are simply ignored, but at least all ASCII characters are supported. The maximum size of the string depends on its content, but about more than 2,000 characters will be critical due to the limited size of Malbolge programs. The basic idea for the program is executing a brute-force search over some specific Malbolge commands for each byte of the output string.
The following Malbolge program prints "Hello World!\n":