The csg2csg tool is a minimal dependency Python3 based program to facilitate the comparison of radiation transport Monte Carlo codes. The csg2csg can currently parse MCNP and OpenMC geometry descriptions, and it can subsequently export MCNP, FLUKA, PHITS, OpenMC and Serpent geometry files. This translation is achieved by reading the input geometry into a class based system of objects corresponding to surfaces, cells, materials and so on. The objects are then translated into a 'generic' form. This form once generalised can be converted to any of the supported code formats and then radiation transport calculations can be performed. The code has been tested on several geometries; most notably a complex JET model and a 70k cell ITER C-Model geometry. [ABSTRACT FROM AUTHOR]