The openOBC project consists of a circuit board designed to replace the '80s era electronics used in the OBC in the BMW E36. What started in a Bimmerforums thread as an idea to modify the firmware in the OBC eventually became the completely redesigned circuit board which is today the openOBC project.
The current openOBC board features a fully user-programmable LPC1769 microcontroller. You might recognize it as essentially the same one used in the LPC1768 mbed. In fact, the openOBC board will happily run any code compiled for the mbed and anyone who has access to the mbed compiler can use it to write code for the openOBC board. However, the official openOBC codebase is not written for/in the mbed environment so you'll still need to set up your own toolchain to compile the source code if you wish to play with the official openOBC firmware yourself. This is easier than it sounds and is highly recommended for just about anyone.
If anyone has trouble getting any of the parts, leave a comment below. If an appropriate substitute can't be found in your part of the world, I don't mind providing the missing parts. Where possible, these parts can be designed out in future revisions.