This is a programming project that I did in Processing. You can check it out on my github, just click on the canvas and press any key to generate a new tree. I worked on this one on and off for a long time. It was actually one of the first things that I tried making when I first started using Processing, but I wasn't good enough at programming back then to make it work. All of the code is in the webpage if you're interested. It's commented...pretty well. Feel free to dig through it. I also made a pretty cool 3D version, the source for that is also on github. Processing is great. I don't often take on huge projects with programming, but I do really enjoy these little things. Processing is perfect for that.