Not Really There is no need for backward compatibility. Each extension can check the version of Thunderbird. If the extension is designed for a new version of Thunderbird and is not compatible with older versions it can fail to install since it is not compatible. Users just use older versions of extensions. In this case where the fault is NOT with the web mail provider there is no need for backward compatibility.
On Tuesday, September 4, 2012 3:45:24 PM UTC-7, jr78 wrote: > > Remember that the Author also wants to keep in place backwards > compatiblity. This is going to take some real coding magic. The reason > being is this, Mozilla says they have now plugged the main cause of memory > leaks in Firefox add-ons. Add-ons commonly hold extra copies of sites in > memory when they don't need to, and the browser now has a mechanism to > detect this and reclaim the memory. I would believe this to be true for > Thunderbird too. >
