Most of my programs are 32 bit, therefore they won't work on MacOS Catalina. The exceptions are CleanEject and JaVaWa IMGname, these two are 64 bit.
With the release of OS X 10.8 Mountain Lion Apple has introduced a new security feature: Gatekeeper. With Gatekeeper it isn't possible to install just any application; only those that are distributed through the Mac App Store and/or are signed with a certificate. To obtain such a certificate for your applications a developer needs to join the "Mac Developer Program" at an annual fee of $ 99. Very nice, but when you give away your software for free it's becoming an expensive hobby... (yes, I do get donations now and then, and no, that doesn't cover the Apple fee)
So the JaVaWa applications won't make it to the Mac App Store, and won't get a certificate.
When you download a JaVaWa application and try to run it, you will get the following message:
There are two ways to solve this. The first one is to change the security setting of Gatekeeper through "System Preferences..." > "Security &Beveiliging en privacy" > "General". When you select "Anywhere" under "Allow applications downloaded from:" you can start the application as usual.
This isn't the best option, because this applies to any application you download. The second option is more preferrable: Open Finder, navigate to the folder where the application resides (usually "Applications"), and click with the secondary mouse button (or Ctrl-click) on the application icon; choose "Open" in the menu. Now you will get the following message:
When you click "Open" the application will start up normally. You need to do this only once; macOS remembers your choice. The next time you can start the application in the usual way.
Many of my programs are available in Dutch and English (and some in French). A German user of Yosemite reported that my programs used Dutch for the interface, instead of the default English. When the same happens to you, this is the solution:
Open System Preferences > Language & Region > Language, click (+) to add the English language (if it's not already present in the list). Then drag it to the second position on the list, so that you have your own language at the top and English next (as your second language).
If an app does not have resources for the first language on the list, macOS should use the resources for the next language on the list. If you're not using English it's good to have English on the second position, because if an app is not translated to your language, the English version will be used. If you have only one language on the list, Yosemite assumes another language as the "fallback plan" for apps not localized to your language.This solution was posted by user "g-7" on MacRumors