NorthernWind is a simple, lightweight Java™-based Content Management System. Small footprint, easy learning curve and simple infrastructure requirements: perfect for small and medium sized websites.
Simplicity is the core principle of NorthernWind: "don't use things that you don't need". Simple websites don't need complex technology and bloated deployments. That's why in its simpler configuration NorthernWind is just 6MB of bytecode.
On the other hand, NorthernWind is expandable. Using Java best practices and relying on Spring, it's easy to replace components or add new ones.
The core abstraction of NorthernWind is the logical filesystem. Why to use a database when a filesystem is what you need to store your documents? The filesystem can be implemented on different foundations, such a physical filesystem, a .zip file, a Mercurial or Git repository; even a database, if you really need it.
NorthernWind is so simple that it can be easily embedded in another webapplication. For instance, it can be used as a rational way to publish static contents within a dynamic webapp. For this reason, its frontend is available in different technologies: Spring MVC, Vaadin, Wicket. And it's easy to implement it with the web framework you like.