In 2006, SilverStripe Ltd decided to rebuild its CMS from scratch in PHP5, with three goals in mind: supporting larger customers with more complex web sites, taking advantage of the experience gained from five years of commercial CMS development, and providing a new codebase to release as open source software. Version 2.0 of SilverStripe CMS was released in February 2007 under the BSD license.
Underneath that CMS was our own custom-built web application framework. We wanted a framework that would take full advantage of PHP5's features, and in 2006 there were very few out there that did. We built our own framework, tailoring it to the needs of a content management system, and named it Sapphire.
Since 2006 SilverStripe CMS and SilverStripe Framework have developed in parallel. Most of the developer-focused tools that SilverStripe CMS provides are actually part of the framework, but in the past we haven't made the distinction very explicit.
Alongside the release of SilverStripe CMS 3.0 due late 2011, we are releasing SilverStripe Framework as a standalone framework. Anyone who has built sites with SilverStripe CMS will be able to create web applications in a familiar environment, and newcomers to SilverStripe CMS will find the SilverStripe Framework a great choice for quickly building an application around a changing data model, thanks to its flexible ORM and form scaffolding.