This is an early development release. I am currently working a lot on JSesh, and I've just added undo/redo capabilities, plus a verification before exiting the program, but it has not been completely tested.
Note that the "Download" page will bring you to JSesh version 3.0, not to this one.
So, by installing it you are more or less acting as beta tester.
Windows users : I haven't made a window specific installer right now, so you should probably try to install this version in your User documents, not in the "Program File" part of the disk.
(the link below to "window installer" is a dead link. Use the first link instead).