SpiderWorks LLC on Wednesday announced the publication of an e-book version of Dave Mark’s seminal ” Learn C on the Macintosh,” now updated for Mac OS X. Mark takes neophyte Mac programmers through a complete course in programming C using Apple’s own free Xcode tools. It’s been published in PDF format and costs US$14.95. Downloadable Xcode project examples are available to customers who buy the e-book. A free preview is available from the Web site.