Mozilla Labs is retiring its Prism project in favor of the new Chromeless experiment. Prism allowed you to create desktop-like apps out of individual websites. Chromeless is a similar, though much more ambitious web-to-desktop project.
Because of the overlap between the two, Mozilla Labs has decided to stop developing Prism. If you’re a fan of Prism, rest assured that you can still use any apps you’ve created with Prism, but there won’t be any further development on the project. It’s unclear what that will mean in the long run for apps like Zimbra, which rely heavily on Prism.
The Chromeless project, which was announced last year, also aims to bring web development to the desktop. But where Prism essentially captured a website and isolated it as a standalone app, Chromeless adds a new set of APIs that allow apps to interact with the desktop like a native application.
For now though Chromeless is still a very experimental effort and a long way from complete. If you’re interested in learning more, head over to the Chromeless page on Mozilla Labs.