A "crossgrade license" or simply "crossgrade" is appropriate if you have already purchased either the Macintosh or Windows edition of our Periodic Table software, and now want to add a license for the other operating system.
The Macintosh and Windows registration systems are not cross-compatible; a Macintosh registration code will not register the Windows edition of our Periodic Table software, and vice versa.
Crossgrade licenses are somewhat less expensive than purchasing "full" Macintosh or Windows licenses.
An "upgrade license" is needed if you purchased Periodic Table prior to October 1, 2004. You will need to purchase an upgrade license to utilize all the features in Periodic Table 4.
If you wish to purchase a crossgrade license for a site license, please contact us.