HCTS testing enables you to certify server, desktop, and laptop systems and many different types of components. In December 2008, Sun released HCTS 4.2, which replaces HCTS 4.1. The HCTS program lets IHVs, system manufacturers, system integrators, and users certify systems and components for the Solaris OS on x86 and x64 platforms. All hardware that passes testing is eligible to be included in the Solaris OS Hardware Compatibility List (HCL).