Berkeley DB的介绍:
They are embedded databases.
They are maps.
They are not accessed declaratively.
They can be transactional. (no sql)
They are persistent.
国外的应用案例:The most famous example is probably Cisco's use of Berkeley DB in its routers, but there are many others. For example, the Subversion version control system stores its repository in Berkeley DB. And Motorola is embedding Berkeley DB in smart phones.