TRiP98 was the very first treatment planning system for scanned carbon ion beams, used to plan the 430 patients enrolled in the GSI pilot project. Since the end of the project, TRiP98 has been used mainly by the GSI Biophysics, but also by other institutes, for a wide range of research applications.

TRiP98 features an analytical dose engine validated for multiple ions, also simultaneously, as well as OER- and RBE-models. TRiP98 supports several motion mitigation strategies, with research focusing on (robust) 4D-optimization, and furthermore arc and CSI plans.

TRiP98 is written in C and features a script language to control planning and simulation tasks. Custom interfaces exist to generate training data for or interact with AI models.