3D modeling software "Metasequoia" official web site
The number that you can enter the serial ID to PC or Mac is defined in the Terms of Service. It depends on your usage patterns.
If Metasequoia 4user is only one person, you can enter the serial ID to your own computers up to two. The computer includes both a Windows PC or Mac.
If you want to use Metasequoia 4 on three or more computers, you need to add new license.
And, if you install the Metasequoia to a shared computer by multiple users, the license can be entered to one computer only.
Serial ID can authenticate both for Windows(32bit/64bit) and macOS / OS X.
In one PC or Mac, you can install multiple Metasequoia. Please count the license on a per-machine basis.