ClassicPress is the fork of WordPress, made on the basis of WordPress 4.9. It was created as a response to the inclusion of Gutenberg into the WordPress core with version 5.0.
ClassicPress was launched by Scott Bowler in August of 2018, and it is currently in the Beta #2 stage for version 1.0. ClassiPress was made on the base of WordPress 4.9.8, and it also includes all the fixes from 4.9.9. So, it is very much the same as WordPress 5.0, minus the Gutenberg editor.
ClassicPress offers an easy way to upgrade from WordPress to ClassicPress without losing any data, plugins of themes used, and right now, all plugins and themes should be compatible with WordPress (that is if they don’t check for the version numbers since ClassicPress starts from the 1.0). ClassicPress is a great solution for anyone wanting to continue to use WordPress, but without the Gutenberg Block Editor. Sure, you can use WordPress without Block editor, but, a lot of users might prefer a clean solution and the direction the ClassicPress is heading.
ClassicPress is currently preparing for 1.0 release (Beta #2 is now available), and you can monitor the proposed features for it and for the future versions, with a lot of things planned to be moved from the core into plugins. While a lot of proposed features might introduce breaking changes in the future, the goal of the ClassicPress is to maintain plugins and themes compatibility with WordPress 4.9 branch for as long as possible, giving enough time for plugin developers to adjust and support ClassicPress in the future along with WordPress.
And, I have decided to officially support ClassicPress, and right now, all Dev4Press plugins and addons should work with ClassicPress 1.0. If you use ClassicPress and notice any issues with any Dev4Press plugins or addons, please let me know, and I will check it out and fix it. All Dev4Press plugins pages now include ClassicPress version requirements, and plugin Requirements pages are updated to include ClassicPress information along with the WordPress.
Also, I plan to write on Dev4Press Blog about ClassicPress, including important announcements, compatibility changes, tests and more. Also, in the next few weeks, there will be few more updates to the Dev4Press website to include ClassicPress in the support forum, to add ClassicPress test website and more.
If you want to learn more about ClassicPress, get involved with the development or support it in other ways, start from the ClassicPress home page.