XRF

XRF is a stack-based esoteric programming language designed by User:Scoppini in 2015.

Overview
XRF operates on a stack of nonnegative integers of arbitrary size, which is initialized with a single 0 value. XRF programs are divided into 5-command "chunks", which are seperated by whitespace. Execution begins with the first chunk. When the end of a chunk is reached, the program moves on to the chunk corresponding to the top value of the stack, where the first chunk corresponds with 0. The commands are:

All characters other than  are not allowed and will cause an error.

Hello, World! program
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Cat program
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Truth-machine

 * Here!

Random generator
A program that generates random output consisting of characters '0' and '1'. Never terminates. 53374 43745 43745 43745 43374 BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB 74235 BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB BBBBB D31AF D31AF

Quine
Here: http://yiap.nfshost.com/esoteric/xrf/quine.xrf This quine is large (~280kb) and extremely slow if run on the original Python interpreter. In fact, a faster interpreter was written in C to allow the program to be run (the quine's author let it run for four hours before understanding that a faster solution was needed).

An alternative interpreter
For running larger, time and memory consuming programs, one might use XRFaster, an interpreter written in C and designed to be fast. However, this particular interpreter does not implement XRF fully; commands 0, 8, C, and D are not implemented because they do not appear in the quine for the sake of which this interpreter was written in the first place. Neither does it perform any error-checking, so your programs need to be perfectly valid.

External resources

 * Interpreter written in python