(The act of telling someone) everything one knows about a particular topic. Typically used when someone is going to let a new party maintain a piece of code. Conceptually analogous to an operating system core dump in that it saves a lot of useful state before an exit. "You'll have to give me a brain dump on FOOBAR before you start your new job at HackerCorp." At Sun, this is also known as "TOI" (transfer of information).