The latest version of Bryce (v7.1 Pro) is still available for purchase (it's actually currently on sale at 23% off) on the website of the programs current owner (ownership changed like 4-5 times over the years) :
https://www.daz3d.com/bryce-7-proBryce 7 definitely works on Win7, presumably it also works on more recent versions of Windows,
the latest version of MacOS that Bryce will run on is MacOS 10.6
More details about OS compatibility and other Bryce-related issues, questions, and content can be found on the Bryce community forum at:
https://www.daz3d.com/forums/categories/bryce-discussionN.B. Bryce is only a 32-bit application, as such it's limited to using around 2Gb of RAM by default. However it's possible to about double the amount of RAM that Bryce can access by installing a small app called 'Large Address Aware'
https://www.techpowerup.com/forums/threads/large-address-aware.112556/#NotSponsored
