Spectral unmixing has emerged as a key application arising from the wealth of spectral measurements in hyperspectral processing. Several communities have shown great interest in the decompositional analysis of mixed pixels. Unmixing provides the ability to decompose mixed pixels in terms of distinct, unique substances, and provide a foundation for doing sub-pixel material identification. We undertake this comparison of unmixing algorithm performance with the knowledge that many algorithms exist, and new methods are constantly being explored and tested. Several disciplines are participating in the attempt to perform unmixing, such as geology, geophysics, engineering, and analytical chemistry.