Seeing the name and being unfamiliar with "J"Edit, I had hopes this was an open source version of the 1982-~2018 commercial "K"Edit editor.

I've been using Kedit for some time as my daily editor, but its lack of UTF-8 support is becoming more dire by the year. Still, the IBM ISPF/Xedit roots and Rexx support make for a powerful environment. An overview of such "Eastern Orthodox" text editors is on SoftPanorama:

http://www.softpanorama.org/Editors/eoe.shtml

A fascinating account of someone productively using Kedit is included in the following article by John McPhee, of all people:

https://archive.mith.umd.edu/engl668k/wp-content/uploads/201...