You can install your CineForm product(s) on as many machines as you like, however only two activated machines are permitted per serial number at one time (one desktop and one laptop).
If you have a workflow environment where you need to move around your activation to different machines you can easily do this using the deactivation techniques described here on our support site.
NOTE: The license itself is not cross-platform. If you own a Windows license, you cannot activate it on the Mac. If you own a Mac license, you cannot activate it on a Windows machine. Some of our resellers offer cross-platform licenses, however they are not cross-platfom in the sense that you can install them on both Windows and Mac. Once you have activated one of these 'cross-platform' licenses on a particular OS, it is then locked into that OS.
ANOTHER NOTE: If you need to play CineForm files but don't need to render into the CineForm format on a particular machine, you can use our free GoPro/CineForm Decoder. The GoPro/CineForm decoder installs a non-expiring decoder plus the After Effects CineForm File Importer.