Tokyo Cabinet is a library of routines for managing a database. The database is a simple data file containing records, each is a pair of a key and a value. Every key and value is serial bytes with variable length. Both binary data and character string can be used as a key and a value. There is neither concept of data tables nor data types. Records are organized in hash table, B+ tree, or fixed-length array. Tokyo Cabinet is developed as the successor of GDBM and QDBM on the following purposes. They are achieved and Tokyo Cabinet replaces conventional DBM products. improves space efficiency : smaller size of database file. improves time efficiency : faster processing speed. improves parallelism : higher performance in multi-thread environment. improves usability : simplified API. improves robustness : database file is not corrupted even under catastrophic situation. supports 64-bit architecture : enormous memory space and database file are available. Tokyo Cabinet is written in the C language, and provided as API of C, Perl, Ruby, Java, and Lua. Tokyo Cabinet is available on platforms which have API conforming to C99 and POSIX. Tokyo Cabinet is a free software licensed under the GNU Lesser General Public License.