Library Design is Language Design,
- Bell Labs proverb
and vice vera.
- Andrew R. Koenig
... Designing a general library is much harder than designing an ordinary program. A program solution to a particular context, but a library must be the solution to a set of problems encountered in a number of projects. An ordinary program can make strong assumptions about its environment, but a good library has to operate successful in the contexts provided by a number of programs. ...
- Bjarne Stroustrup, The C++ Programming Language 2nd Edition, Chapter 13. Design of Libraries