Mass spectrometric software suite for (bio)-polymers. GNU polyxmass features an integrated mass spectrometry framework where users are able to define brand new polymer chemistries (within the polyxdef module), and use these definitions in order to make simple mass calculations (within the polyxcalc module) or perform complex simulations of polymer chemistry with related mass data computations (within the polyxedit module). The framework allows full customization of every aspect of the polymer chemistry being defined, and of the way the polymer sequences are graphically displayed. This program was formerly called "polyXmass".