You have several Xojo and Real Studio versions in use?
You want to know in advance what Xojo version a project was saved with?
Please try our plug-in for QuickLook: MBS-Xojo-QuickLook-Plugin.dmg
After installation of our plug-in to /Library/QuickLook and you run "qlmanage -r" in Terminal app or logged in the next time, your icons look like this:
This plug-in is freeware, so please share with friends and enjoy!