Install or Uninstall Addons for your site, we call Addons for Infusions.
An Infusion can be Infused [installed] or Defused [un-installed].

Infusions : The names of all uploaded Infusions in your infusions folder.
Status : Not Infused, The Infusions have been uploaded but not yet Infused.
Status : Infused, The Infusion have been Infused.
Upgrade Available: These are displayed when installed infusions that have a new version uploaded but not yet updated.

You can Download Addons from our AddonDB

Each Addon downloaded from PHPFusion Main should contain a readme file that explains how to install.