IBM Rational ClearCase is a software configuration management tool that works in both the UNIX and Microsoft Windows worlds. With its powerful command line interface and triggers, ClearCase can be easily customized for the needs of end users.
MultiSite is a ClearCase add-on tool that enables you to replicate the main ClearCase database, called the VOB, to several sites. MultiSite can be set up so that the synchronization of the databases is done automatically. Also, MultiSite has an automatic transfer of mastership concept, which enables it to automatically transfer the mastership (e.g. the ability to change an object) from site to site.
IBM Rational ClearQuest is a change management tool that can easily track the change requests in a software project. For example, it can track the defects found, the new features that need to be implemented, and so on. ClearQuest, via the ClearQuest Designer, can also be customized for the needs of end users.
ClearQuest also has a MultiSite add-on the enables you to replicate ClearQuest databases to several sites. It uses the same mechanisms and concepts as for ClearCase MultiSite, but ClearQuest MultiSite does not support transfer of mastership.