Stacy Quandt, an analyst at the Robert Frances Group, said that IBM's endorsement of Firefox internally aligns with the company's strategy of backing open-source products based on standards. It may also give other companies reason to "pay attention to" Firefox and see it as an alternative to Internet Explorer.More details at CNET
IBM encourages employees to use Firefox

IBM encouraged its employees to start using Firefox instead of Microsoft's Internet Explorer. Currently about 10 percent, 30,000 people, of IBM's staff, uses the Firefox browser.