The MolProp TK provides a customizable framework for molecular property calculation geared towards enabling rapid database filtering. Filtering attempts to eliminate inappropriate or undesirable compounds from a large set before beginning to use them in modelling studies. The goal is to remove all of the compounds that should not be suggested to a medicinal chemist as a potential hit. This exercise is obviously case dependent, depending on ease of the assay, intended target, personal bias of the modeller & medicinal chemist, strengths of the company, etc. which makes this problem one that is highly amenable to a toolkit solution.