So we asked ourselves a big question. What would we build if we were starting from scratch today, knowing all we’ve learned over the past 13 years of building WordPress? At the beginning of last year, we decided to start experimenting and see.

Today we’re announcing something brand new, a new approach to WordPress, and open sourcing the code behind it. The project, codenamed Calypso, is the culmination of more than 20 months of work by dozens of the most talented engineers and designers I’ve had the pleasure of working with (127 contributors with over 26,000 commits!).

Source: Dance to Calypso | Matt Mullenweg

Today, Automattic open-sourced the codebase that runs WordPress.com. This new codebase is entirely API driven and includes technologies such as Node.js and React.

With my background being in developing WordPress themes for an agency, this past year has been one hell of a roller coaster ride as I’ve learned to work with this new stack. And while there were some stressful times as I retooled, I’m super excited for what I and we have been able to do

For more background on why we decided to rebuild WordPress.com, see Matt’s post titled Dance to Calypso.

For some insight into how this project was approached, see The Story Behind the New WordPress.com