These are the main sources of Isabelle/jEdit, which is a plugin for
the jEdit text-editor, with some minor modifications according to
patches/.
Original jEdit is available from http://www.jedit.org -- it is
licensed according to GPL, and the derivative version produced in
directory "dist" inherits that.
Note that Isabelle repository versions refer to a contributed
component called jedit_build-JJJJMMDD, which also includes the full
sources after applying the patches, together with further add-on
modules.