Pydio (alias AjaXplorer) is a online file-sharing platform. It provides a desktop-like folder and grouping structure. It can integrate with LDAP and other authorization schemes, also provides enterprise feature and a custom syncing protocol. Pydio runs on PHP with modern browsers, but also provides clients for Android / iOS, and a Thunderbird plugin. It's distributed under a Affero GPLv3 w/ CLA, for redistribution as commercial variant.
OpenXava is a Java Framework for rapid web application development and easy AJAX utilization. Business logic and associating data structures are sufficient for generating interactive frontends. It's compatible to a wide range of open source and proprietary plattforms, including databases, application servers and enterprise repositories.
WebDraw is a demonstration of server-side mouse tracking using AJAX over HTTP.