Microsoft released Office Web Apps Browser Plugin for Firefox for Office 2003 &  Office 2007 users which lets them open Office documents directly from Firefox into appropriate Office desktop application. For example, in Word Web app clicking “open in Word” results in document being opened in Word 2003 or 2007.  When the  opened Word document is saved, it is saved back to the web location where it was opened.

Using Office Web Apps Browser Plugin

1. Download and install the plugin to your Computer, restart Firefox browser if opened at the time of installation.

2.  Open the document in Office Web Apps, click the command (Open in Word, Open in Excel or Open in PowerPoint) to open the document in the Office desktop application.

Office 2003 or Office 2007 users need to use this plugin for their Firefox browsers. However Office 2010 users need not install this plugin as it will be installed automatically with the install of Office 2010.

Office Web Apps  Browser Plugin works in Firefox 3.5 & above versions. Word, Excel, PowerPoint Web apps are supported with this plugin.

You need to be using Office 2003 (SP3) or Office 2007 SP2 for this plugin to work as advertised.

Download Office Web App Plugin