Versatile: You can strip down to a core system, or build up with 3rd-party addons.

Full API documentation

High coding standards: No PHP notices. Type-strict codebase. MVC framework.

Free online developer's guide book (in the tutorials)

Custom field filters: For example, restrict news posts to a minimum length.

Stack traces for easy debugging

Synchronise data between staging and live sites using Resource-fs

Breadcrumb overrides

Advanced banning: Set your own banning rules for different hack attack codes. Even create your own ban pages (e.g. to mimic law enforcement bans for spammers).

Code overrides: Implement modifications to the Composr code without directly editing the original code by creating _custom files. This makes upgrading much easier. Also supports contentious_overrides hooks and the override_api for more advanced overriding.

Many different hook types allowing for modifying or extending Composr without modifying or overriding the code.