Sun Microsystems' (nasdaq: SUNW - news - people ) exit door opened a little wider this week after President and Chief Operating Officer Ed Zander, 55, announced he was leaving. In 15 years at Sun, Zander was instrumental in establishing Sun's Solaris software as the leading platform for Unix network computing. Zander took his current position in 1998 and helped to flatten Sun's disparate units--from hardware to chips to software--into a more level reporting structure. Effective July 1, Chairman and Chief Executive Scott McNealy will take over Zander's duties, reassuming the additional title of president. The company said it does not intend to name a replacement for Zander. More...