Floobits brings real-time collaborative editing to text editors, IDEs. Collaborative text editors and screen sharing solutions usually suffer from the following problems:

Users are confined to looking at the same thing.
Only one user can edit at a time.
One person is usually stuck in an unfamiliar editor.
Only 2 people can work at a time.

We started building Floobits for ourselves to address these concerns. Floobits allows multiple users to simultaneously edit any file using the text editors they already know.

Riot allows teams to communicate across a wide range of collaboration apps. If some team members use Riot while others use IRC, Slack or Gitter, Riot will allow these team members to seamlessly work together. Riot offers the richest network of communication bridges. Riot lets you run your own server, and provides users and teams with the most advanced crypto ratchet technology available today for a decentralized secure Internet. Riot is entirely open source: all the code is published on GitHub (Apache License) for anyone to see and extend. This means teams can customize or contribute to the code and everyone can benefit from the speed of community innovation. Riot is built on top of Matrix.

Query Editor: think of JS Fiddle for SQL queries. It's your way to share data in the organization in an open way, by sharing both the dataset and the query that generated it.
Visualizations: once you have a dataset, you can create different visualizations out of it.
Dashboards: combine several visualizations into a single dashboard.

gitfs is a FUSE file system that fully integrates with git. You can mount a remote repository’s branch locally, and any subsequent changes made to the files will be automatically committed to the remote.

TogetherJS is a free, open source JavaScript library by Mozilla that adds collaboration features and tools to your website. By adding TogetherJS to your site, your users can help each other out on a website in real time!

A fun and easy way to share ideas on a website

MobWrite converts forms and web applications into collaborative environments. Create a simple single-user system, add one line of JavaScript, and instantly get a collaborative system.

A community-curated database of well-known people, places, and things

JS Bin is a tool for experimenting with web languages. In particular HTML, CSS and JavaScript, but JS Bin also supports other languages too (like Markdown, Jade and Sass).
JS Bin is ultimately a code sharing site.

Etherpad is an Open Source online editor providing collaborative editing in really real-time powered by Node.js