Guppy is a Javascript-based WYSIWYG editor for mathematics whose content is stored in an XML format that makes Guppy mathematical expressions searchable, parseable, and renderable.
The content of the editor can easily be extracted in a well-annotated XML format (for searching), as well as LaTeX (for rendering), plain text (for text applications) or a syntax tree (for manipulating/evaluating).
A full live demo can be found at http://daniel3735928559.github.io/guppy/site
A standalone basic demo can be found at http://daniel3735928559.github.io/guppy/site/examples/basic
Go to the quickstart page.
Also check the FAQ.
Yes! There are many at the examples page.
Of particular note are:
Editor content is stored in a specific XML format. Editing operations then correspond to operations on that XML.
Yes! See the contributors page for how, and the roadmap for an idea of where the project is heading.
Guppy is licensed under the MIT License.