Microsoft's latest 10-K adds Canonical, distributor of Ubuntu Linux, to the list of acknowledged competitors for Microsoft's Client division, which makes Windows for PCs. Also notable’s the addition of Linux distributor Red Hat to the list of Client divison rivals. Previously, Red Hat was mentioned only as a competitor for the Microsoft Business and Server & Tools divisions. New in the browser competition’re Google, Apple and Opera.  Last year's filing listed only Mozilla. Also new in that section is Google Android, reported.