X-ray Computed Tomography (CT) methods can be used to study the internal structure of geomaterials nondestructively and with minor sample preparation. Previously, such methods have been utilized in the characterization of petroleum reservoirs, underground water resources, soil, ores, and carbon storage in aquifers. We describe the development of a flexible scripting system, FLEXT, to control the components of a non-commercial multiscale X-ray CT scanner for geological applications. This X-ray CT system, with allied hardware and software, can characterize geomaterials at multiple length scales and as a function of time - in the dynamic imaging mode. This multiscale and dynamic imaging system enables flexible imaging of geomaterials with open hardware and software architectures that permit programming, scripting, and modifications. The modifiable custom-built X-ray CT scanner is capable of imaging objects as large as 20 cm to smaller than 1 mm with three stages. Flow equipment that may be integrated into the software system permits realistic dynamic imaging experiments. Imaging of three rock samples at the 120-mm, 40-mm, and 2-mm length scales are presented as well as two dynamic evaporation experiments in a model glass-bead pack and a natural chalk core plug. The developed imaging system accelerates hardware and software modifications and permits new applications and discoveries in geosciences.