It's lightweight and supports over 100 unique languages open-sourced, autocompletion, vim/emacs/sublime binding, linter integration, themes, inline and block widgets. I must say MIT has done an excellent job.

Having used CodeMirror for several projects, I am a staunch supporter of this product. It performed well above and beyond all expectations.

It is an incredible code editor the truth to be so little known to other than that is completely free that in my opinion it is something very good, it also has a fairly powerful and extensive API that allows us to work much better and more comfortable. This editor has many features that make it stand out as the fact that it highlights the syntax so that the reading and writing of the code becomes more enjoyable and simple, in addition to that it makes the spacing and places the indentation automatically, we can also manipulate , create or edit large documents, with thousands of lines of code without any problem and with great fluidity. Finally, I really like that it has an extensive range of languages that it supports and that in addition to that we have the option of autocomplete that when it comes to coding becomes a great friend.