Suites are how a plug-in communicates back to the host. A suite is simply a set of function pointers in a C struct. The set of suites a host needs to implement is defined by the API being implemented. A suite is fetched from a host via the OfxHost::fetchSuite function. This returns a pointer (cast to void * ) to the named and versioned set of functions. By using this suite fetching mechanism, there is no symbolic dependancy from the plug-in to the host, and APIs can be easily expandable without causing backwards compatability issues.

If the host does not implement a requested suite, or the requested version of that suite, then it should return NULL.