From a 1998 NYTimes article on Jeff Citron and Datek:
"One reason for Datek's success was its innovative software programs like Watcher and the Monster Key -- programs that other S.O.E.S. houses eventually licensed or mimicked. Mr. Citron and Mr. Levine, meanwhile, created an array of companies to orbit around Datek, including Smith Wall Associates, a computer services concern that had sales of $100 million in 1996. It was from many of these companies that the two say they made much of their fortunes, tens of millions of dollars. They even won over regulators by developing an electronic stock exchange called Island, a system that now handles about 4 percent of all Nasdaq trading volume."
Wonder where Josh Levine is now? I don't think he's still at josh.com. {Update: Yes, he is, though his blog is now hosted by WordPress.)