Exalogic is a computer appliance made by Oracle Corporation, commercially available since 2010. It is a cluster of x86-64-servers running Oracle Linux or Solaris preinstalled.
Its full trade mark is Oracle Exalogic Elastic Cloud (derived from the SI prefix exa- and -logic, probably from Weblogic), positioned by the vendor as a preconfigured clustered application server to use for cloud computing with elastic computing abilities.