Thunderbird 6 for developers

This page is not complete.

This content covers features introduced in Thunderbird 6

This page lists the changes in Thunderbird 6 that are relevant for developers. For changes that are relevant to end users, see

Gecko 6.0

Thunderbird 6 is based on Gecko 6.0. The Firefox 6 page has details on the significant changes to Gecko.

Changes for Mozilla and add-on developers

For helpful tips on updating existing extensions for Thunderbird 5, see Updating extensions for Firefox 4. There are several key changes that break compatibility with existing add-ons, so be sure to read that article.


Backend changes


Other Changes


More resources

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, trevorh, Sheppy, Potappo, Standard8
 Last updated by: chrisdavidmills,