http://audio-video.gnu.org/video/ghm2009/ghm2009-dolstra-large.ogg http://audio-video.gnu.org/video/ghm2009/ghm2009-dolstra-lar... this talk by Eelco is a good

http://audio-video.gnu.org/video/ghm2009/ghm2009-dolstra-large.ogg http://audio-video.gnu.org/video/ghm2009/ghm2009-dolstra-lar... this talk by Eelco is a good introduction for hacker types. And the motivation is at the beginning of the talk.