The integrated database retrieval system DBGET/LinkDB is the backbone of the Japanese GenomeNet service. DBGET is used to search and extract entries from a wide range of molecular biology databases, while LinkDB is used to search and compute links between entries in different databases. DBGET/LinkDB is designed to be a network distributed database system with an open architecture, which is suitable for incorporating local databases or establishing a specialized server environment. It also has an advantage of simple architecture allowing rapid daily updates of all the major databases. The WWW version of DBGET/LinkDB at GenomeNet is integrated with other search tools, such as BLAST, FASTA and MOTIF, and with local helper applications, such as RasMol. In addition to factual links between database entries, LinkDB is being extended to included similarity links and biological links toward computerization of logical reasoning processes.