Atlas API architecture. MySqlDb, Seq, SeqGet and SeqLoad classes/modules (grey) are available in all three languages: C++, Java, and Perl. The SeqLoad and Seqloader modules are created in C++ only as these are tightly coupled to the NCBI C++ Toolkit. All other classes are available in Java. Applications share the common modules SeqLoad, SeqGet, InteractionLoad, and InteractionGet which provide the methods necessary for loading and retrieval operations, to and from the databases. These modules employ additional classes (not shown) that are representative of the major data model components such as Sequence, Interaction, Interactor, and Dbxref, for example.