LPL is a new and efficient, structured modeling language to build, modify and document small as well as large, real live LP models. The model building process, surprisingly neglected up to now, is an iterative process and, therefore, the most time consuming step. This may be a reason, that Operations Research techniques still find a limited usage in commercial practice. The development of the LPL language was motivated by practical modeling tasks. The available LPL Compiler generates automatically the MPSX input files of large LP models.