Autobot is a computer program designed to perform automated editing of the English-language Wikipedia. It is currently not approved to edit the main encyclopedia. It is run as User:RichardcavellBot by Richard Cavell. Autobot is open source, free software. You are welcome to build and run the program on your own computer, in which case you will need to gain approval for your version of the bot at WP:BRFA.
Richard Cavell wrote the original version of Autobot himself over a week in late February 2011. After getting feedback from various developers, he then refactored and completely rewrote it over the next week. He then open-sourced the code here : SourceForge. The code is hosted on an SVN repository. There are currently 3 code contributors: Richard, Guenter and Justin. You are welcome to join the project if you would like to contribute.
Autobot is written in the C programming language. It's written in C99, but only a few features of C99 are actually used. The rest is C89. The code is about 4300 lines in 12 source files. The resulting executable is about 50 kilobytes in size. It uses the libcurl library to access Wikipedia. XML parsing is done manually.