The library contains a collection of MINLP problems in GAMS language gathered from practical or academic optimization problems. The ideal of one of the founders, Alexander Meeraus was to create an accessible code and language, such that all the world could study the same type of problems. The GAMS languagee wants to promote this idea, although the company also developed translating codes to other modelling languages.
It is used as a benchmark to compare different codes for MINLP.
Bussieck M R, Drud A S, Meeraus A (2003) MINLPLib - A Collection of Test Models for Mixed-Integer Nonlinear Programming, INFORMS J. Comput 15(1). (pdf)