Ilmatar was the next tradewind in the alphabetic sequence of Tablet/Maemo/MeeGo OSes after Harmattan. I guess it was the same UI as Harmattan but adopting "full" Meego compatibility through using RPM packaging etc. And maybe tablet and keyboard additions to the UX from ajalkane's link (but I assume this would have still been an ARM build).

Makes me chuckle that Nokia was unable to release two devices to consumers using the same OS - that might have made it follow quickly after the N9! No, best re-tool things and make it incompatible with the last one for user confusion and delays! They never learn(t)!

I never understood the big excitement with the whole MeeGo thing anyway. Ok, a unified platform for multiple companies to us would be a good thing, but Nokia were the ones with a proven track record of shipping good and popular devices on their Linux platform, whereas Moblin from Intel's side was never used in anything so widely (afaik). I just feel like Nokia wasted their time trying to merge with something not very well proven and got no benefits from it.