CodeMirror 6 is a new code editor libraryfor the web, a from-scratch implementation based on the experience ofbuilding and maintaining versions 1 to 5 for the past 13 years. Itaims to be more extensible and accessible than previous versions.

As of today, version 6.0 is stable. Going forward, probably at leastseveral years, all new releases will be under the 6 major version, andbe backwards compatible.

The library has been usable and largely stable for over a year, withonly minor breaking changes. I generally prefer to release late, toavoid having too many regrettable mistakes slip into the stablerelease, which would then have to be kept there indefinitely. Withouta doubt there will be things that, a year from now, I wish I hadreleased differently, but by having users work with the code inproduction for a significant amount of time, a lot of small issues andsources of friction have been found and resolved before being set downin stone.

Work on this system started four years ago, with PrototypeFund funding the initial work. It wasannounced publicly and crowd-funded a year after that, built out intoa useable system in the two years after that, and refined andstabilized in the past year. During the first two years, Icollaborated with Adrian Heine on the design and implementation of theinitial system.

For some more background on the new library, see the blog posts onLezer (the parser system), facets (theextension system), and collaborativeediting. For an overview of the entiresystem, take a look at the systemguide. For a rough summary ofwhat changed in the interface since 5.x, see the migrationguide.