When we started to develop the library we decided to equip our implementations of external memory data structure and algorithms with well known generic interfaces of data structures and algorithms from the Standard Template Library, which is a part of C++ standard. This choice would shorten the application development times, since the time to learn new interfaces is saved. Porting internal memory code that relies on STL would also be easy, since interfaces of STL-user layer data structures (containers in the STL terminology) and algorithms have the same syntax and semantics. Another advantage is that compatible interfaces will allow to reuse the I/O-efficient code, existing in STL (e.g. scanning and selection algorithms).