Mail Server Tutorial: This session is aimed at administrators who can't or won't use 3rd-party mail hosting (and who would?) but still need a reliable, spam- and virus-resistant mail server. A basic knowledge of BSD, smtp and dns is expected and required.
Mercurial is a modern, open source, distributed version control system, and a compelling upgrade from older systems like Subversion. In this user-friendly, six-part tutorial, Joel Spolsky teaches you the key concepts.