Last week, a company I'm partnered with was looking at spending $10000 on buying the Percussion CM System, and paying $5k a year for support and maintenance. Percussion's features? In-context editing, fine grained work-flow and publishing, drag and drop asset control, and in-site css editing. Extensibility and integration with third party apps was limited to whatever html embeddable widgets provided by services like google maps, facebook, and so forth. For the version we were being sold, there is no API.

We choked on the $5k a year requirement, and started looking at alternatives. Our business case is relatively simple. We need a system from which we can manage several dozen client websites, assisting with content generation, management, and workflow, and allowing the client to have total control over look and feel, workflow, and add-ons.

I started by looking at Joomla, but the usability for non-webmasters is, well, nonexistent. It's clunky and has a big learning curve. I and my clients can't afford the time to waste figuring out the backend.

My next target was drupal, which suffers from similar problems. Plone, at least, has the permissions, finegrained workflow control, and multitenancy built in, but it's too much, and I couldn't install it after 8 hours of wrestling with my webserver.

I will recommend Plone to those looking for a site system that has significant enterprise application requirements, which need python support and its robust scalability. 99% of my use cases are not going to need that level of requirements, and c5 provides the last 20% of usability that Plone lacks.

So, I've chosen concrete5 over a $15k commercial system, because frankly, you kick their ass in features and flexibility, and go straight toe to toe on usability.

Oh yeah - the backend code, the peer-review plugins, and the MIT licensing? You're doing it right. I like your style.

My hat is off to the developers. I look forward to a long and profitable relationship with c5. :)