Changes

'''Ask Questions and Get Help''': Developers are encouraged to get help and advice in the mozilla.dev.apps.thunderbird newsgroup (the traditional venue) or in tb-planning mailing list. (see [[Thunderbird/CommunicationChannels#If_you.27re_a_developer|Communication Channels]] Please check this document and ask questions in a forum before filing a bug report. Also, test and fix your add-on using a [httphttps://wwwgetthunderbird.mozilla.org/thunderbird/channel/ beta com version60 release] of Thunderbird - do not use nightly builds (currently version 63) for testing changes intended for version 60.

'''Legacy, pre-version 57 add-ons''' - '''Thunderbird 57-60 (and Seamonkey) <u>still support</u> legacy add-ons''', but all add-on authors must check to see whether code changes are needed. The complexity of the add-on determines how it is affected - many add-ons are not heavily affected, some not affected at all. '''Some add-ons do not need any code changes, and some only trivial or minor refactoring or name changes. Some need to adapt to changed interfaces. Some only need changes to startup and intialization, others may need more extensive changes.''' A non-eshaustive details exhaustive list of of things to be modified is listed below. Every beta from 57 to 60 delivered changes. So for example if your add-on is compatible with beta 58 you may still need to make further changes. Example changes to version 59 involve {{bug|1414398}} default preferences, and {{Bug|1419145}} menu to access add-on options and tab options.

'''WebExtension''' aka futures: Thunderbird 60 does not have WebExtensions support. Going forwards, {{bug|1396172}} will be add WebExtension support in Thunderbird beta 63, while maintaining "legacy" add-ons and hybrid add-ons.