With Xcode 11 through 14, Reality Composer for Mac has been included with Xcode.
Apples's own documentation states:
"You automatically get Reality Composer for macOS when you install Xcode 11 or later. The app is one of the developer tools bundled with Xcode. From the menu, choose Xcode > Open Developer Tool, and select Reality Composer."
This simply not the case with Xcode 15. In fact, we cannot even open existing RCPROJECTS such as the classic Experience.rcproject found in Apple's own sample code Creating a Game with Reality Composer.
As an AR developer this makes my currently project virtual unworkable. It's my understanding that when Reality Composer Pro is finally released -- it will only be compatible with visionOS apps, as opposed to iOS apps that are built with RealityKit; this was certainly the case with early iterations.
Apple's Creation tools for spatial apps still mention Reality Composer, but it is only available for iOS and iPadOS. Taking away such a critical tool without notice is crippling, to say the least. Any official announcements on the future state RealityKit development would be welcome.