According to the eysos website,
eyeos is an open source web desktop following the cloud computing concept. It is mainly written in PHP, XML, and Javascript. It acts as a platform for web applications written using the eyeos Toolkit. It includes a Desktop environment with 67 applications and system utilities. It is accessible by portable devices via its mobile front end. eyeos lets you upload your files and work with them no matter where you are. It contains applications like Word Processor, Address Book, PDF reader, and many more developed by the community