The fpdbfexport module is part of the FreePascal FCL database modules. This export module provides export to DBF formats (e.g. DBase IV format). This format is still popular because it is simple, and - opposed to e.g. csv - is clear about what data type is enclosed in its fields. Many spreadsheet and database programs can import DBF files.
Limitations and known bugs
In FPC 2.6.2 (e.g. supplied with Lazarus 1.0.8), exporting to e.g. dbase IV format - that has a 10 character field length limit - of fields with longer field names will throw an error unless you populate the export fieldname mapping yourself.
This bug has been fixed in FPC trunk revision 24490 See 
See the examples in your FPC source directory $(fpcdir)\source\packages\fcl-db\tests (see Databases#Running_FPC_database_tests), specifically testdbexport.pas.
The various export formats are run in TestDBFExport_DBaseIV, TestDBFExport_DBaseVII, TestDBFExport_FoxPro, etc.
The procedure TTestDBExport.GenericExportTest shows how you can export to only supported field types (handy if you do not know in advance what field types are used in a dataset).