In Form Builder, when you add a Formatted Text Area field to a form, under the hood Orbeon Forms uses the TinyMCE library. For Orbeon Forms 2020.1, we've upgraded TinyMCE to version 5. TinyMCE 5 provides better accessibility, stricter WCAG 2.1 compliance, and more.
While we were at it, we've also rewritten the Orbeon Forms client-side code that deals with the TinyMCE library in Scala.js, in the process doing some clean-up, and making that code easier to maintain in the future.
We've also made a few subtle changes to how the control shows out-of-the-box, like reducing the space taken by icons in the toolbar, having text users type show in the same font as text typed in other fields, and adding slightly rounded corners as done for other fields.
In general, this is part of the work we are doing under the hood to modernize our code and upgrade the libraries Orbeon Forms is using, which, in aggregate, contributes to improving maintainability, performance, compatibility, accessibility, and more.