Additionally, it can easily be embedded in Qt4/C++ applications.
Hosted on GitLab, see Repo, Wiki
There is also a Qt5 version, see: Repo, Wiki; worthwhile to mention is the integration with QML, including some interesting examples, as Lisp and QML play very nice together.
There is also an android and an iOS port of it, which works with both QML and traditional QWidgets, see EQL5-Android and EQL5-iOS.
License: MIT