Sun Microsystems CEO Jonathan Schwartz, an advocate of Web 2.0, used Twitter early Thursday to announce his resignation. He was named CEO in 2006 as Sun faced a switch in strategic direction away from proprietary systems and toward open source code, including its valued Solaris 10 operating system.

"Today's my last day at Sun. I'll miss it," he said in a tweet to his followers, reported the New York Times on its Web site at 1:12 a.m. Thursday. He added a bit of haiku: "Financial crisis, Stalled too many customers, CEO no more."

Schwartz was the first CEO of a major company to use the blogging format to announce his positions and comment on issues in the industry. He advocated that blogs be given the same status as press releases with the Securities Exchange Commission. The New York Times observed that he's the first Fortune 200 executive to use Twitter to announce his resignation.

With a short ponytail and an academic look, Schwartz embodied Sun's attempt to change direction in 2006 and get astride the currents then moving through the computer industry. Sun already had a strong position in Java and operating system software with Solaris. He sought to expand it into Java middleware, such as application servers, as well as identity management and portal software. It was an approach that was gaining traction as the second major recession of the 21st century hit in 2008-2009. Sun had never fully recovered from the dotcom bust of 2001, and its revenue took a steep hit.

Few had expected Schwartz to survive the completion of Sun's acquisition by Oracle. In late 2008, Schwartz had been an advocate of Sun being acquired by IBM. Those talks stalled in March 2009, and chairman Scott McNealy helped engineer a deal, announced April 20, with Oracle instead. Sun shareholders approved the acquisition July 16, but the agreement's completion dragged out until late January as the European Commission reviewed it for anti-competitive issues. Sun was also rumored to have sought a deal with HP before it signed the deal with Oracle.