Q: Why does Firefox use Acrobat Reader to display PDFs on Debathena?

Answer

Users whose Firefox profiles were created on Athena 9 may find that PDFs open Acrobat Reader instead of the default PDF reader, Evince. Acrobat Reader will taken longer to launch than Evince because it is stored in AFS, not on the local disk.

To change your preferred PDF reader, open the Firefox preferences window (Edit -> Preferences) and select the "Applications" tab.

To revert to the new default versions for Firefox "helper applications", remove the mimeTypes.rdf file from your Firefox profile directory.