I've noticed that El Capitan has a new Extensions preference pane and most searching I've done talks about Photos can now use 3rd party extensions to make it more useful. OK, that's great, but from what I've seen in the preference pane there's more to it than just extensions for the Photos App (e.g. it looks like one could have extensions for the Notifications panels and more). The question is just how many new areas support extensions in El Capitan? What else could be added other than extensions for the Photos App?
Obviously, I'm thinking about things like Quicktime X (AV Foundation). I don't suppose there's any new extensibility there so that something like Quicklook could be expanded to support .AVI or .MKV formats via an extension to Quicktime X. I doubt it, but I have to ask anyway. Losing Perian plugin support in Mavericks when the new AVFoundation "Quicktime X" was added had to be one of the worst changes in OS X history as it makes it considerably less functional on a day-to-day basis (kind of like many of their newer "Pro" apps like Final Cut Pro remake was less functional than the old one and lost Apple a lot of customers in the process and Apple continues to act like they simply don't care if anyone uses a Mac anymore for anything).
Obviously, I'm thinking about things like Quicktime X (AV Foundation). I don't suppose there's any new extensibility there so that something like Quicklook could be expanded to support .AVI or .MKV formats via an extension to Quicktime X. I doubt it, but I have to ask anyway. Losing Perian plugin support in Mavericks when the new AVFoundation "Quicktime X" was added had to be one of the worst changes in OS X history as it makes it considerably less functional on a day-to-day basis (kind of like many of their newer "Pro" apps like Final Cut Pro remake was less functional than the old one and lost Apple a lot of customers in the process and Apple continues to act like they simply don't care if anyone uses a Mac anymore for anything).