Extension Versioning in Firefox and Thunderbird 1.5
Now that Firefox and Thunderbird 1.5 beta 2 have been released, extension authors should begin checking their extensions for compatibility, and update the extension maxVersion number appropriately for the 1.5 final release.
Security and stability releases of Firefox and Thunderbird will be numbered
1.5.0.1
1.5.0.2
1.5.0.3
These security/stability releases will be API-compatible with Firefox 1.5; extensions that are compatible with 1.5 should assume that they will be compatible with all security releases. These release numbers will be used for the extension version check: extension authors should therefore mark their extension maxVersion as “1.5.0.*”, which indicates that the extension is compatible with future stability releases. If the extension maxVersion is set only to “1.5″, the stability releases will cause the extension to be disabled.