GeoTrace http://www.geotrace.com/
Provides high technology seismic data processing services and software to the oil and gas industry worldwide.
GprMax - Numerical Simulator for GPR http://www.gprmax.org/
GprMax 2D and 3D numerical simulator for Ground Penetrating Radar. Free to use for research and teaching purposes and can be used to create synthetic GPR responses from complex targets.
Sandmeier Scientific Software http://www.ka.shuttle.de/software/
Ground-Penetrating-Radar ( GPR ) and reflection/refraction-seismic data processing software as well as solutions for various other near-surface geophysical applications like ultrasound and geoelectric.