Just to summarize a few general concepts available within FlowBasis...

• Pages can contain controls which can contain other controls.
• Pages and controls can communicate from browser to server via remote procedure calls (JSON-RPC).
• Modules (blog, wiki, etc) contain resources (posts, comments, pages, etc).
• Resources are indexed for searching.
• Modules (blog, wiki, etc) or other sources can publish widgets (recent posts, tag cloud, html snippets) that can be embedded in other pages.
• Resources can be rated.
• Anything can publish events to the event manager. Anything can subscribe to events with an event handler.
• Task handlers can be registered to perform tasks that must be done periodically in the background (like cleaning cache).
• Installers manage adding and removing features/modules/whatever from the system.
• Permissions define what users can do within modules (such as post an entry to a blog).
• Users can have roles which grant them permissions (such as only admin and author could post an entry to a blog).
• Roles can apply to specific contexts (user can be admin for whole site or just a particular blog).
• Themes collaborate with pages and controls to determine the visual style of the site.