Sun Microsystems Inc. makes its money selling Unix computers, but this week plans to unveil what it promises will be a new and improved "software strategy" that will promote the development of Web services. Services are server applications built with components that rely on protocols such as HTTP and XML to interact over the Web. Microsoft Corp. has a similar scheme with its .Net project. Sun will have to deliver, or have partners deliver, development tools needed to make the initiative something programmers can use to build such services. Microsoft has a beta-test version of its .Net tool set and a development kit for Simple Object Access Protocol, which lets one component call, or trigger, another over the 'Net.