When developing with gvSIG it is useful to know the existing plugins, especially the functionality provided by the ApplicationManager. But the important thing is to control which of the libraries we will require in order to implement the functionality we need.

In version 2.0.0 of gvSIG major changes have been introduced, both in how to build gvSIG as well as in the nomenclature used to identify the projects and libraries that are generated. However, this is not a process that has taken place suddenly, it has been happening over a number of years. This has now resulted in a lack of uniformity in the nomenclature of existing components. When it comes to referring to a library we can use the Eclipse project name, the name of the generated jar, or the Maven artifact name. In projects generated recently the chosen rule is that these three names must match, with the name of the Maven artifact being used for all three. Prior to this decision projects had different names for each of these components. For a developer who intends using gvSIG, the important thing is to know the names of the Maven artifact, since they usually need to know for which artifacts dependencies should be set, with the eclipse project name associated with that artifact being less relevant.

The libraries that most meet our needs in gvSIG are:

• org.gvsig.tools.lib contains structural utilities. Already mentioned at the beginning of the document so we won't elaborate on it at this point.
• org.gvsig.fmap.geometry (libFMap_geometries). The library for managing gvSIG's geometries. Presents a geometry model with an API independent of its implementation.
• org.gvsig.projection (libProjection). The library for managing gvSIG's coordinate reference systems.
• org.gvsig.fmap.dal (libFMap_DAL). The data access library of gvSIG (Data Access Library). It is used by all projects in one form or another to access to a shape, dxf, a PostgreSQL table, a GML, a WFS layer or a DGN file. It presents a common API for accessing vector and tabular data or for accessing coverages.
• org.gvsig.fmap.mapcontext (libFMap_mapcontext). Contains the API and implementation of layers and map at the logical level.
• org.gvsig.fmap.control (libFMap_controls). Contains swing components that are linked to the logical components that are presented in the DAL library and mapcontext. It could be a visual component for displaying a map or presenting a table obtained from the DAL.
• org.gvsig.crs (libJCRS). Is an API implementation of the projections from org.gvsig.projection.
• org.gvsig.symbology.lib.api. Contains the API of gvSIG's symbology library.
• org.gvsig.ui (libUIComponent). This is a library that houses a series of general utility graphical components.