does KDE support .desktop files from Gnome?
I'm a Gnome user and trying to figure out the easiest way for elder people to download some file with their browser and launch it.

If it's a .sh script, then youll need to explain how to make it
executable before clicking.
For Gnome users you can put a short command into a .desktop file.
(This command should check the existance of .sh file, download the .sh
file with wget, make it executable and launch it)
Don't know about KDE though.

It should be freedesktop.org -specific, not Gnome-specific, but just to make sure

Both kde and gnome use the same desktop file structure as defined by the freedesktop standard, so in general they should be compatible. But there may be some desktop-specific additions that won't be recognized.

http://standards.freedesktop.org/des...ec-latest.html

The best thing to do is simply to try them out.