Apple released MacOS Catalina 10.15 yesterday. The download is huge at 8 GB. I have installed it on one of my Beta drives for testing. I run bunches of Apps on my iMac. Many App Developers are releasing Catalina App updates as we speak. However, some have said they are still working on fixing certain things so they work in Catalina. So, here is the deal. If you have Apps which are mission critical that still need updating, I would hold off on installing Catalina. If you believe your main Apps are good to go then go ahead and install it. Just have a good backup and/or clone of your machine before doing the upgrade.