A library that allows to edit any HTML document using rich primitives. I’m curious about the implementation, but I think having a wrapper around contenteditable=true nodes that controls the state of the HTML, and especially what can be pasted in is gold. The problem is selection management, though.

10015.io is a “free all-in-one toolbox” solution created to ease your life by preventing bookmark mess.

GrapesJS is an open-source, multi-purpose, Web Builder Framework which combines different tools and features to build HTML.