The Defense Threat Reduction Agency (DTRA) has purchased two spectral analysis programs, RobWin and RSEMCA, to support arms control efforts. This thesis explored which program performed better for nuclear weapon identification and verification. The initial hypothesis was that both programs would perform similarly with only small differences in visual displays and operating functions. The thesis investigated three areas in order to evaluate the software's capabilities. The first area studied the benefits offered by different detectors, specifically the NaI and CZT detector. The second area analyzed the quantitative and qualitative capabilities of each program, and the third area reviewed the software's ability to detect weapon grade plutonium (WGPu). The results of the study show that RobWin performed better then RSEMCA. Only RobWin is capable of supporting DTRA's needs in treaty verification. RSEMCA is incapable of identifying WGPu due to a mathematical error associated with the peak count calculations. The detectors used in this thesis, the CZT and NaI, also failed to support DTRA's needs. Neither detector was capable of acquiring the necessary spectrum for identifying WGPu. Because of this thesis, recommendations were made for future work with CZT detectors, nuclear weapon detection, and software development.