DirSync uses a version of the MicrosoftForefrontIdentityManager(FIM)2010R2synchronizationservicemanager, pre-configured for synchronizing user, group, and contact objects from onpremises ActiveDirectory to Office365. This pre-configuration is why DirSync is referred to as a "software appliance" (set and forget); DirSync is 64-bit only, earlier 32-bit appliances are now unsupported.