Microsoft Corp. will stop developing a version of its Windows Media Player for Apple Computer Inc.'s Macs, and will instead offer free technology that lets people play Windows Media files using Apple's own software. The company decided to stop developing the Mac version so it could focus on efforts for Vista, the new version of Microsoft's Windows operating system that is due out later this year, said Tim Harader, a senior business development manager with Microsoft's Windows digital media division. "We've been so focused on Vista and we've been so focused on creating an incredible media experience on the PC," Harader said Friday. "We just did not have the resources to do a good job on (the Mac version)." Apple computers represent about 4 percent of the US market. PCs running Microsoft's Windows operating system comprise the vast majority.