Concrete5 is an easy-to-use yet highly functional CMS (content management system).

The CMS is built in a way that allows administrators to quickly edit the content; many of the current users of concrete5 are schools, and the easiness of using conrete5 makes it a perfect school-CMS.

The tip-top features of this CMS are:

• Built-in SEO tools (add tracking codes and meta tags without touching the code)
• Free support for every single client
• Flexible design options
• Pre-made addons (more complex addons cost money though!)
• WYSIWYG content editing

Basically, the main reason why you could prefer this to existing platforms is that you can build larger&more complex websites than with WordPress – whilst still keeping the CMS usable and easy to edit.

• Website: http://www.concrete5.org/

GetSimple is a clean and simple Content Management System, and its 2.01 release was released recently.

Their motto, “GetSimple has everything your client needs, and nothing a CMS doesn’t”, is remarkable. Because there aren’t that many developers that put that much thought into usability.

The CMS basically features everything a CMS needs. The data is stored in XML files, so no MySQL is involved.

GetSimple has an “Undo” function, which allows undoing almost every action.

It is easy to theme, easy to use, and great for small websites. Your clients will love it.

• Website: http://get-simple.info/
• Demo: http://www.opensourcecms.com/demo/1/269/GetSimple+CMS

Merengue is a nice, Django-based CMS. Written in Python, this CMS shines in keeping itself easily plugin-able and with a clean code.

The tip-top features of Merengue include:

• Collaborative editing (great for news-sites)
• Built-in geolocation
• Numerous gadgets and a feature-rich dashboard
• Easy internationalization
• Easy back-ups
• Skinnable look

Although there are hundreds of CMS’s out there, Python programmers will love this one, as there are few fully-functional Python-based CMS up to date.

• Website: http://www.merengueproject.org/
• Demo: http://demo.merengueproject.org/

Ionize is an easy-to-use content management system with an emphasis on a customizable design.

The features of Ionize include:

• Intuitive UI–you can use Ionize for clients with no WP/Drupal knowledge
• Customizable ad infinitum (CodeIgniter)
• Multilingual core
• Built-in user management
• Easy media linking
• An easy templating language

It’s also made in France, so that’s a bonus if you’re looking for exotic systems. ;)

The demo’s username & passsword: demo / demo.

• Website: http://www.ionizecms.com/
• Demo: http://demo.ionizecms.com/admin

Vosao is a CMS written in Java. It is made to be distribute on the Google App Engine.

The main features of this CMS are:

• Free hosting with Google Apps (up to 500mb storage and 5,000,000 monthly pageviews!)
• WYSIWYG Worpress-like editing of pages and posts
• Designer friendly templates
• Loads of extensions

Vosao is arguably the most powerful content management system that runs on Google App Engine; others usually being either too simple or too hard to get into, with the possible exception of stoutsd.

• Website: http://www.vosao.org/
• Demo: http://vosaocms.appspot.com/

In case you missed LightNEasy’s latest update on June 29th (or missed this CMS completely)… you should really look into it.

Recently, LightNEasy’s development has shifted towards developing two separate versions – LightNEasy for the MySQL version, and LightNEasy Mini for the no-database version.

However, the two share a very similar set of features:

• Easy templating
• Creating, adding, and editing pages
• Updating the code of pages
• Several plugins for various purposes
• SEO-friendly structure

Both versions also have built-in templates, so this CMS is especially useful for people with little knowledge in the field.

• Website: http://www.lightneasy.org/
• Demo: http://demoflat.lightneasy.org/