Open source CMS, nice UI

The Secretary is an open source portfolio management, or content management system, made specifically for designers, artists, photographers, musicians - essentially anyone with an online portfolio. It is simple, clean, lightweight, user-friendly, easy-to-use, straightforward and highly customisable and extendable.

An easy, flexible, empowering Content Management System for rapid development that transforms your CodeIgniter projects into client manageable brilliance.

Picking up where Frog CMS left off.

Nice looking CMS for businesses. Ecommerce, newsletters, crm, analytics, etc.

Stacey is an easier way to create a portfolio site. No database setup or installation files, simply drop the application on a server and it runs. Your content is managed by creating folders and editing text files. No login screens, no ‘cms’.

Good article on the various CMS options that are out there.

Looks very promising.

GetSimple has everything your client needs, and nothing a CMS doesn't.

Melody is an open source content management system for bloggers and publishers where its community of users and contributors is its most important feature.

Barcamp Event and Content Management System: This is a web-based-wordpress-powered system aimed at helping people running unconferences manage their event's content in a more organized manner.

TypePublish is a PHP/MySQL-based website content management system and application framework. It is ideal for small-to-medium businesses who want to set up and manage their own websites. It's also perfect for web developers who want to build fast and elegant websites and online applications on behalf of their clients.

Surreal CMS is a remotely hosted content management system (CMS) that was designed with simplicity in mind. Most people who can browse the Web will be able to use Surreal CMS with little to no training.

Open Source ColdFusion CMS

FlatPress is an open-source standard-compliant multi-lingual extensible blogging engine which does not require a database to work.

I took a look at this briefly and it looks like an interesting CMS.

Frog CMS share the goal to simplify content management, and offer an elegant user interface, flexible templating per page, simple user management and permissions and all what you need for your files management.

gelato is a tumblelog CMS built on AJAX, PHP and MySQL.

A good article written by D.Keith Robinson carrying on the conversation about content management systems.

The first CMS built by designers for designers, is the claim. UI looks nice, nothing new as I can see as far as functionality and features.