They themselves didn’t know, actually. Until someone told them to look at the Acknowledgements. (If you have Safari 5 installed you can check it out yourself, the Acknowledgments can be found in the Help menu.)

Neither did I. So I find it strange that in news articles like this one: http://travel.nytimes.com/2010/06/13/travel/13Harry.html?hp Readability still does a better job then the Reader extension that is based on it.

Readability is able to include the images and presents something that doesn't look like a poorly printed page like, sorry guys, the Reader thing does.

I imagine that "thank a developer for using a bookmarklet" is pretty low on the priority list of people trying to implement this feature. Wayyy below "guess where Steve's mood is going, so we can get him at a time he'll think this deserves the precious screen space".