Here are some projects of mine.
onion-expose is a utility that allows one to easily create and control temporary Tor onion services. onion-expose can be used for any sort of TCP traffic, from simple HTTP to Internet radio to Minecraft to SSH servers. It can also be used to expose individual files and allow you to request them from another computer. GitHub.
Pager 2 is an extremely simple, drop-in SPA library. I use it for many of my random projects; it saves writing the boilerplate every time. GitHub.
Jeva is a web microframework who want to write something in Java (as opposed to Python). GitHub.
RollCall is an HTML5-based Skype replacement that can do full-res encrypted video calls and encrypted messaging. Although the crypto used in the messaging isn't great (it doesn't do PFS), it' still worth a look, and fully functional. GitHub.
I got bored once, so I took about 45 minutes to implement the Mandelbrot set in Processing. After getting a rudimentary implementation to work, I spent a few hours afterwards implementing Julia sets, color coding, stopping after things stop being eliminated, and some configurability (in the form of a whole bunch of fudge factors). The code is still a bit messy, but it's worth a look. Gist.