Mark Dalrymple, the Advanced Mac OS X instructor at Big Nerd Ranch, has been a Macintosh programmer since 1985 and a professional Unix programmer since 1990.
Mark has experience on the client side and server side, being a veteran of several startups and larger technology operations like AOL and Google. On the back-end, he has been the technical lead for AOLserver, a high-performance web server handling tens of thousands of hits per second on many different Unix platforms (Linux, HP, SGI, Digital Alpha, Solaris). On the client-side, he has worked with native Mac toolkits, helped in the construction of cross-platform toolkits, and currently has code running on millions of Macintosh desktops world-wide.
Mark is principal author of Learn Objective-C on the Macintosh and has been the technical reviewer for many Cocoa and iPhone titles with Apress. He is also the co-founder of CocoaHeads, the international Mac programmer's group, with chapters in 26 countries on five continents.