This section presents an overview of the packages that make up the TMAPI 1.0 release. As already noted, TMAPI has been built to be modular so that new functionality can be added to the API in a piecemeal way without upsetting existing implementations. To keep things clean from an implementation perspective, each piece of functionality is defined in its own separate package in the API. The current (1.0) version of TMAPI defines three packages, org.tmapi.core which provides the basic interfaces for accessing topic map processing systems and the information that they hold; org.tmapi.index which defines a simple common index API for opening, refreshing and closing indexes as well as retrieving metadata about an index; and org.tmapi.index.core which defines a set of basic indexes.