When it comes to programming, for the most part I fiddle with esoteric programming languages. A noninclusive list of things follows.
There is an interesting 2D
programming language called Befunge.
fungot is an IRC bot written in the Funge-98 version of the language.
As far as I am aware, it's one of the largest hand-written
Funge-98 programs there are.
Features of fungot include interpreters for the brainfuck and Underload languages, support for user-defined commands in the above-mentioned languages, as well as an ngram-based babble generator with various styles.
Most of the time you can find fungot on the channel #esoteric in the freenode IRC network.
It also has a periodically active Twitter account.
The main source file is fungot.b98. The GitHub repository there also contains some other files necessary for running it.
Speaking of Befunge, I have also written a somewhat speedy interpreter for the older, more limited Befunge-93 variant of it.
It is called ff, and it is but a single file of C: ff3.c. (The 3 is a version number of sorts.)
Continuing on the topic of esolangs, I'm responsible of a set of BF Joust implementations. You can find them and their documentation at a GitHub repository.
robotfindskitten is a Zen simulation
that has been ported to incredibly many sorts of systems.
In it, you assume control of a robot, looking for kitten amongst many non-kitten items (NKI).
rfk86 is a port of it to the TI-86 graphing calculator.
It has its very own website.
mcmap is a Minecraft automap that works by proxying the connection between the Minecraft client and server, and extracting the world information from the traffic.
I wrote the initial version in late 2010; other people have worked on it, too.
Caveat: it might not always be very speedily updated to be compatible with the latest Minecraft versions.
mcmap has a GitHub repository.
zpaste is a simple, single-user (or not-too-many-user) pastebin/tinyurl hybrid, in case you want something a bit more tweakable than the myriad of web services around.
GitHub repository.
Let me just quote from the README:
This is a GTK+ program to use the input devices (keyboard, mouse) of one computer as the input devices of a remote computer, via VNC. Think of it as a sort of a DIY "Synergy". The main benefit, compared to an actual VNC client, is significantly improved latency in some cases, as it never actually requests the screen contents from the remote computer.
Find it by cloning/downloading gist 2017454.