DOJO is a javascript based toolkit. It offers a pretty comprehensive offering of widgets, APIs for image annotation and many more lightweight controls. Image annotation capabilities were of particular interest to us.

We wanted to develop an online document proofing system. Requirements were to allow users to annotate, markup and make comments on documents using a browser based application over the internet. We did not want to use any client side plugin like silverlight or flash, since that could act as a deterrent for use.

We were able to accomplish most of the functionality like image annotations, markup using DOJO toolkit. We used other javascript based libraries for zooming and image rotation functionality.

Please visit for more details about DOJO toolkit.