The current Openfire (formerly Wildfire) documentation can be found below. All documentation is also distributed in each release.
Guides that are applicable to most administrators of an Openfire instance. These cover the basics.
The following guides cover more specialized topics. These aren't necessarily applicable to every Openfire installation.
Openfire is written to facilitate integration with existing data sources, such as external user directories or custom database. The guides in this section describe how such integration can be achieved.
Guides for developers that work with the Openfire source code.
Guides for implementors of custom integration of external authentication, users and other entities.
Openfire is an XMPP server. It can therefor be used by any application that implements this protocol. This section lists a number of minimal examples using various libraries (mostly third-party) that illustrate how they can be used to interact with Openfire. Note that there are many other libraries available than the ones listed here!