Support for Opalis Integration Server on Microsoft Windows 64-bit Operating Systems - TechNet Articles - United States (English) - TechNet Wiki

Opalis Integration Server is not supported on any 64-bit edition of Microsoft Windows.  Opalis Integration Server may successfully function under a 64-bit environment, however this has not been thoroughly tested and may result in unexpected errors and/or poor application performance.

Using x64 hardware does not necessarily require that a 64-bit Operating System be installed. Because the x64 architecture is an extension of the x86 architecture, all x86-based Operating Systems will install and run natively as a 32-bit Operating System and as such is considered a supported state.

Using IA-64 hardware is not supported at all as this hardware is a completely different architecture that does not run 32-bit Operating Systems.