Hexagony
Hexagony was created by me, Martin Büttner, in September 2015.
As far as I know it is the first two-dimensional programming language which operates on a hexagonal grid (instead of the usual rectangular grid). To make matters worse, opposite edges of the grid wrap around, making the topology of the source code a weird twisted torus. To make matters worst, the memory model is also a hexagonal grid, where each edge holds an integer value. Considering these things, I think the name (being a portmanteau of "hexagon" and "agony") is completely justified.
My prime checker and the Hexagony self-unfolder contain fairly detailed explanations of the language's quirks and show how to program in it.
- GitHub repository. Includes interpreter (Ruby), language specification, example programs and issue tracker.
- Esolangs page. Largely a copy of the README.md on GitHub.
- Esoteric IDEEsoteric IDE by Timwi which contains another implementation (C#) and a graphical debugger (yep).
- Hexagony Colorer also by Timwi. This is a tool which can be used to annotate execution paths in Hexagony source code. See this answer for an example of the result.
- Try it online! (by Dennis) backed by the Ruby interpreter.
- Showcase your language entry (written by Adnan).