Apple’s OS X comes nowhere near Windows in terms of market share, but it is making significant progress at Microsoft’s expense. According to market research firm Net Applications, Apple’s share of the operating system market in January was up a quarter percent to 7.57 from December, and up approximately 1.35 percentage points in the past 12 months.

Although OS X is still a long ways off from breaking even with Windows, Microsoft has to be a bit concerned about how it is slowly bleeding market share to OS X. If Apple maintains the pace it set in 2007, it should crack the 8 percent mark by the end of April and possibly double its market share by 2011 – according to Gartner. Meanwhile, Linux also showed modest gains up from 0.63 percent in December to 0.67 percent in January. Check out Net Applications' operating system trend data here.