* Proper Documentation for the currently endorsed way of developing addons
* Proper Documentation of the API currently endorsed for TB addons to hook into.
* The tools required including perhaps an existing IDE or a way of building one from existing components in order to write the required code, compile, debug, test and finally release.

I have skimmed through all the official documentation given on developing addons for Thunderbird. All I found was either articles marked as "outdated", outright "broken" or led to dead links. For example: * https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Main_Windows [incomplete] * https://developer.mozilla.org/en-US/Add-ons/Thunderbird/HowTos [badly broken] * https://developer.mozilla.org/en-US/Add-ons/Thunderbird/Demo_Addon [says you can download it at the bottom, but is crossed out and link dead] * Want to do some real stuff? See how to inspect a message (demo add-on included!) [Link included leads to 3rd party who is no longer hosting the content] Also somewhere I told me to use WebExtensions to develop future addons because browser-wide support, but its unclear if TB supports that. What I am asking is a single resource that includes the right documentation for the right tools that are required to write TB addons. Especially since I am want to do a from what I see is a minor adjustment. In a more structured fashion here is what I need: * Proper Documentation for the currently endorsed way of developing addons * Proper Documentation of the API currently endorsed for TB addons to hook into. * The tools required including perhaps an existing IDE or a way of building one from existing components in order to write the required code, compile, debug, test and finally release. Cheers!