Each WordPress release cycle is led by one (or more) of the core WordPress developers. The 3.7 release cycle was led by Andrew Nacin, with Dion Hulse and Jon Cave. The 3.8 release cycle was led by Matt Mullenweg. The 3.9 release cycle was led by again by Nacin with a number of others assisting.

A release cycle usually lasts around 4 months from the initial scoping meeting to launch of the version.

A release cycle follows the following pattern:

  • Phase 1: Planning and securing team leads. This is done in the #wordpress-dev chatroom. The release lead discusses features for the next release of WordPress. WordPress contributors get involved with that discussion. The release lead will identify team leads for each of the features.
  • Phase 2: Development work begins. Team leads assemble teams and work on their assigned features. Regular chats are scheduled to ensure the development keeps moving forward.
  • Phase 3: Beta. Betas are released, and beta-testers are asked to start reporting bugs. No more commits for new enhancements or feature requests are carried out from this phase on.
  • Phase 4: Release Candidate. There is a string freeze from this point on. Work is targeted on regressions and blockers only.
  • Phase 5: Launch. WordPress version is launched and made available in the WordPress Admin for updates.

The launch is often followed soon after by a point release as bugs are reported and squashed.

You can learn more about the current release cycle, or follow the development blog for more information.