The WordPress core development team builds WordPress! Follow this site for general updates, status reports, and the occasional code debate. There’s lots of ways to contribute:
A valuable contribution an individual can make to WordPress development is to test WordPress, even if you are not a developer. Before every stable release of WordPress, pre-release versions are made available for testing. You can download the pre-releases and test them, so that the WordPress developers can fix problems before the new version is made available to the public.
If you want to be on the bleeding edge of development, even before pre-release versions are put together, you can also check out the latest software from the WordPress Subversion (SVN) repository. Or, you can get the “nightly build” (which is created from the Subversion repository) — almost as up-to-date as the instantaneous Subversion repository.
To get started, install the WordPress Beta Tester plugin. Visit Plugins > Add New, type “wordpress beta tester” in the search field, and then click/tap “Install Now”.
Backing up first is sensible.
Go to Plugins > Add New and search for “WordPress Beta Tester”
Click or tap the “Install Now” button for the WordPress Beta Tester plugin
Go to Tools > Beta Testing
Select the “Bleeding edge nightlies” option to follow development for the next major release of WordPress, or “Point release nightlies” to follow development of the next point release.
Click or tap the “Save Changes” button
Go to Dashboard > Updates
Click or tap the “Update Now” button
Once the plugin is installed, navigate to Tools > Beta Testing and review the settings:
Point release nightlies. The current release is 5.2.3. Selecting this will put you on the track for 5.2.x development.
Bleeding edge nightlies. Selecting this will put you on the track for 5.3 development.
You can also use WP CLI to directly update your WordPress to trunk version by doing:
New features are often developed as plugins. Feature plugins can be installed from the beta testing tab on the plugin install screen of your WordPress dashboard. Navigate to Plugins > Add New > Beta Testing.
The plugins listed here are proposed for future versions of WordPress. They are glimpses of the future that are under active development. New versions are released regularly, sometimes daily. Some feature plugins require that you follow bleeding edge nightlies.
Tracking bleeding edge nightlies with the beta tester plugin and installing feature plugins will make all of the latest software available for beta testing. If you go this route, here are some useful testing resources (and thank you very much):
make/core is the main WordPress development blog. It is active and will keep you up-to-date on what’s happening right now in WordPress development.
make/flow contains visual records and visual bug reports from the Flow Patrol team.
The Flow Patrol handbook includes information on triage if you want to get into triaging posts on make/flow.
When done testing, rolling your site back to the latest stable production release can be done with a tap/click of “Re-install Now ” on the Dashboard > Updates screen.