Proposed feature for Safari: Markup.

Highlights and notes, with Pencil support, as an overlay atop the original page. Personal, not public, but synced via iCloud. I’d use this every day.

@gruber We actually prototyped something like this over a decade ago but we didn't think anyone but you would use it.
@donmelton @gruber Wasn't there a Firefox plugin or some service that did something similar, but public, circa 2004 or so? I seem to recall something about user notes totally covering every site for users of it almost instantly.
@Chris @donmelton @gruber yes! The web sites sued the pants off of them. It was more like 2000 than 2004.

@wklj And this is yet another reason implementing this feature isn't practical. It's not the biggest reason, but it's definitely the one the lawyers care about the most.

@Chris @gruber