The following forum message was posted by codehunterworks at http://sourceforge.net/projects/synedit/forums/forum/9469/topic/4086893:
As i remember, codefolding was implemented in project Mystix. If you open a
file in mystix, codefolding works fine. But unfortunately when manipulating
the code particularly block operations and undo/redo then folded areas would
be chopped. So this implementation of codefolding was not usable for us.
But i agree with you that some modern features like this or e.g. refactoring
etc. should be implemented. To do this, we must change some major things in
core component TSynEdit.