Kandan.me is an open-source chat app you can use for your collaborative environments.

Kandan is easy to deploy collaborative chat app which can be used on CloudFoundry, Heroku, dotCloud, etc.

Some of its features are rather interesting:

• Unlimited channels;
• Embed videos, images, etc;
• Comes with a ‘companion bot’;
• Highly customizable with plugins.

Kartograph is a Python/JavaScript framework for creating interactive vector maps.

Kartograph’s strong points are:

• Separated map generation and rendering;
• Numerous map types available from the get-go;
• Independent nature which allows for complete designing freedom (doesn’t use Google’s maps).

Overall, Kartograph seems like a good solution for a graphics designer or a data miner. The maps are rendered in typographic quality, so web magazine editors should take a look at this library.

Pligg is a CMS that focuses on user-generated news.

Unlike other CMS like WordPress, Pligg is entirely geared towards having numerous users which all contribute to the site (think Slashdot, Digg or Reddit).

It only requires PHP 5 and MySQL to run correctly.

What you’ll like about Pligg:

• Built-in rating AND comment rating system
• Kick-ass RSS support; users can subscribe to categories, the front page, and more
• User management, profiles, private messaging, etc – all inside the default package
• Available in multiple languages
• Active community

What you won’t like:

• Relatively few add-ons (or modules), and many of them have a price tag
• Infamous previous versions create doubt about Pligg’s safety even now

Aloha is a powerful content editor which allows editing pages on the fly.

Although the front page of their website nearly crashed Opera, the editor works on Chrome; Safari; FireFox; and (wait for it) Internet Explorer.

Aloha works with WordPress too, and the thought about editing content on the fly would make any writer’s inner child weep in anticipation.

Furthermore, if you believe what an imaginary user says about Aloha, using this editor is like “having our own supersonic guinea pig.”