The admin piece is built using Prototype, Scriptaculous and the TinyMCE rich text editor. It uses Object Oriented PHP5 and talks to MySQL backend.

There is a nice feel to using the explorer interface to manage files (e.g. hit rearrange and you can drag and drop), and then seeing your site in preview mode. A really nice touch is being able to see your site in draft, and compare it to the published version

Features

• Simple user interface. Simple, tailored to your site, WYSIWYG editing, easy enough for your Mom to use.
• Easy to customise. Anything you can do with HTML, you can do with the SilverStripe template system.
• Multiple ways of organising navigation. Organise content in more than one hierachy with the use of “virtual pages” or tags.
• Flexible data object model. The database is automatically managed by a rich object-oriented data model. Creating custom data types is a few lines of code away – simply make a sub-class and define the additional fields.
• Multiple templates per page. Every page has a default style, but there’s no need to be restricted by this. Define different templates for your pages.
• Flexible, “plain HTML” templates. You have total control of the HTML produced by SilverStripe; the templates use as much “plain HTML” as possible.
• Seperate “draft site” and “published site”. Staged content enables you to make changes which on a seperate site, before you publish it to the live site that the public can see.
• Asset management. Image resizing, define custom sizes to fit within your template.
  
• Versioning and roll-back. See an audit trail of all changes to your page.
• Full commercial support available. For both developers and end-users.
• Search engine friend. Friendly URLs, Meta-data support, and clean XHTML templates mean that Google will love your site.
• UTF-8 Support. Macrons and other character sets are fully supported.
• RSS. Generate feeds of parts of your site.
• XHTML Compliant.
• Full text search. Easily search your entire site, or just bits of it, including PDF’s and word documents.

homepage:  http://www.silverstripe.com