Type: Plugin Files
Acronym: Mozilla Installer Package
Opens With: Mozilla Firefox, Mozilla Thunderbird, Mozilla Seamonkey
Compressed installation archive used by various Mozilla applications, including Firefox, Thunderbird, and SeaMonkey; may contain the primary components installed with the software, or may contain an software extension, such as a Web-browser plug-in. XPI files can often be installed by simply dragging and dropping the file onto an open Web browser window. They are installed by Mozilla installer script, which is part of the XPInstall component included with the software.