Microsoft on Tuesday released the first service pack for Office 2007, focusing on improvements to stability and performance instead of new features.

"People were generally happy with the tools we've offered in [Office] 2007," Reed Shaffner, product manager for Microsoft Office, said in an interview. "You're not going to hear about a ton of new features." Office 2007 has seen strong sales that Microsoft officials have credited with significantly bolstering the company's financial earnings.

SP1 is available today as a free download from OfficeOnline and will be available as an automatic update between three and six months from now. It will also be available for companies through Windows Server Update Services and Systems Management Server.

Microsoft said in November that Office SP1 wouldn't be available until next year, so it might be considered an early release.

Before release, Microsoft limited beta testing to some large enterprises and internal Microsoft users, an indication that the company believes Office 2007 SP1 isn't as significant as some other products that go through a much more intensive testing phase before release. Shaffner said SP1 shouldn't cause any compatibility problems, but added that companies should test it anyway before releasing it across their businesses.

Most of the changes are relatively minor, including specific fixes to increase stability under certain conditions, including the five bugs that most often crashed each Office application. Other improvements include compatibility with Windows Server 2008, improved performance and better protection from security threats