JNEXT is an open source (triple MPL, GPL, LGPL license), small footprint, cross platform and cross browser framework for extending Web browser Javascript
(for more background and motivation check this blog entry).
With JNEXT it is possible to utilize existing Web browsers to host full and self contained applications that do not depend on external Web servers for the application logic (although they are free to make use of them).
This is acheived by enabling Javascript controlled access to the full range of native operating system
resources (such as TCP/UDP sockets, files, databases, threads etc).