Writing Cross-Browser Extensions is Tough
Note that Cade is reporting purely on the session for porting addons from Firefox to IE. We gave another session on extending IE using some of the incredibly easy extensibility mechanisms like Slices, Accelerators and Visual Search.
The goal of my talk was to cover what you need to do in IE if you want to have common functionality across Firefox -- I committed to the audience to stay away from any functionality that wasn't commonly achievable in both browsers. The other session was about extending IE8 without worrying about Firefox compat; and that is obviously very easy.
My message was that it makes your work harder in *both* Firefox and IE if you want to go cross-browser -- you lose things like XUL UI elements, and you have to use C++ in IE to get XUL equivalents. But it's worth it to target *both* browsers, IMO, since the whole point of the web is universal interop.
Biting the hand that feeds IT
