In the last week, I've become a little obsessed with Caching Server 2 in OS X Server 3. It could be my favorite feature in Mavericks period. What is the Caching server? To quote Apple's documentation: "The Caching server speeds up the download of software distributed by Apple through the Internet." It archives this by storing a local copy of content on-demand when local devices update. Subsequent requests are served from the local cache, over the network, saving Internet download time and bandwidth. This helps everyone: network administrators, device users, and Apple. - Fraser Hess
Awesome overview of Mavericks's caching server.