MX is a fast, lightweight cheminformatics toolkit that can be used in many programming environments. Previous articles have shown how easy it is to use MX in Ruby and Python, but that's just the beginning.
The new jsMolEdit demo page is impressive: it reads molfiles, writes molfiles, and supports interactive drawing features such as moving, editing atoms and bonds, zooming in/out, and atom/bond highlighting.
jsMolEdit doesn't yet support some important features needed by an interactive structure editor, but it's an amazing proof of concept.
There are many other ways to apply the basic concept. For example, I recently wrote about JSpecView, a spectrum viewer/editor deployed as an applet.