The MUFI text editor was built to enable the use of a MUFI (Medieval Unicode Font Initiative) approved font in a web based text editor. I developed it in 2015 for a Stanford Open edX course on medieval manuscript transcription.
The MUFI text editor features simple buttons for coloring and formatting text to match ancient medival manuscripts. It also allows for the insertion of special characters from a custom keyboard.
You can also see the MUFI text editor used live on Stanford'sLagunita Open edX instance
Image of illuminated letter "M" is in the public domain.