The rendering of jicon.gif has some artifacts in modern gradient and composited desktop frames.
Solution is to use smoothly blended to transparency PNG.
Here's a sample from Linux desktop.
And here's the image file 128x128. (Extracted from Mac icns from j602 and saved as PNG.)
Note 1: the size should be at least 64x64 to be also re-used as desktop icon. Java will take case to resample in to 16x16 window thumbnail.
Note 2: just renaming it jicon.gif will also work with current Java frontend.
Linux Desktop Launcher
This could be placed into j602 folder and explained in install.txt how to change paths depending on location.
«j602.desktop»=
[Desktop Entry] Version=1.0 Encoding=UTF-8 Name=j602 Type=Application Exec=/home/user/j602/bin/jwd TryExec= Icon=/home/user/j602/bin/jicon.gif X-GNOME-DocPath= Terminal=false Name[en]=j602 GenericName[en]=j602 Comment[en]=j602 Front End GenericName=j602 Comment=j602 Front End