Tokyo Cabinet - database library features modern implementation of DBM - key / value database e.g.) DBM, NDBM, GDBM, TDB, CDB, Berkeley DB - simple library = process embedded - Successor of QDBM C99 and POSIX compatible, using Pthread, mmap, etc. No actual limit size of a database file (to 8 exabytes) transaction - write ahead logging and shadow paging - ACID