With Office 2010, Microsoft started offering Office Web Apps, which includes free online versions of Microsoft Word, Microsoft Excel, Microsoft PowerPoint, and Microsoft OneNote. Web Apps allows users to access document online from anywhere as well as share files and collaborate with other users online.
Microsoft Office 2010 installs plugin in Firebox web browser which allows documents to be opened directly from web browser into the appropriate Office desktop application.
Firefox updates most of plugins automatically and show warning to users if any update is available to download. Plugin Microsoft Office plugin is unrecognized by Firefox at this time, to update Microsoft Office 2010 plugin for Firefox user needs to update current version of office suite or install available updates of Office Suite from Microsoft’s website.