SilverStripe is an easy to use content management system (CMS) based on PHP. Not only does SilverStripe offer an very cool looking user interface, but is is really simple to get started with and building websites of any size and for any purpose.
SilverStripe is a great and fairly young project (open sourced in October 2006) - that looks incredibly promising.
With the SilverStripe CMS, website editors don't need to know HTML or even be familiar with complex web applications. You can get started in very little time—a typical training session with one of our clients takes no more than an hour or two. You and your staff can quickly start taking advantage of powerful features such as:
-Create new pages and drag and drop them where you want them to be in the sitemap
-Edit and style content using a toolbar with familiar buttons and dropdowns (similar to MS Word)
-Easily insert links, images, and Flash into your content
-Copy and paste content from MS Word
-View a draft of your content changes before pushing them live
-Publish changes to your site with one click of a button
-Assign different user roles and permissions for each section or even page of your site
-View older versions of a page and roll back if needed