Some five months after IBM gave open-source developers unfettered access to 500 of its software patents, the company has turned its attention to the broader concept of <A HREF="http://www.eweek.com/article2/0,1759,1823794,00.asp">harnessing that model to spark innovation,</A> an effort already catching on with other large technology vendors. The open-source licensing and intellectual property model is also attracting some traditional proprietary vendors, such as Nokia Corp., which is testing the waters with new products tailored to developers of open-source applications.