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.

Create web articles and blog posts with equations and diagrams Upmath extremely simplifies this task by using Markdown and LaTeX. It converts the Markdown syntax extended with LaTeX equations support into HTML code you can publish anywhere on the web.

Tables Generator and online editor for HTML, LaTex, Markdown tables.

Test your JavaScript, CSS, HTML or CoffeeScript online with JSFiddle code editor.