Along with two new music channels, XM Satellite Radio today announced that its Internet radio service is now available to Mac users. XM Radio Online, which debuted last month, is now compatible with Apple Safari, Mozilla Firefox, and Netscape Navigator browsers on Macs with Windows Media Player 9.0 installed. The service offers 72 commercial-free music channels and several talk and entertainment programs. XM Radio Online is available for a monthly fee of US$7.99. XM Satellite Radio subscribers can get XM Radio Online for $3.99.