SANDRIFT  For those folks who might seriously wonder about the value (in tax dollars) of this software, I can say that this tool is very useful for those of us who study Mars professionally. The quality or availability of data often is determined by season, illumination conditions (e.g., local time), etc., and being able to have a tool like this helps calculate and visualize conditions on Mars. For scientists and engineers responsible for planning daily rover or orbiter operations, it's even more important to have access to information about things like what time it is at a given site at a given Earth time, what season it is, where the subsolar point is, etc. In short, while this may be a nifty "toy" for the interested public, it's actually a very useful tool for scientists and engineers, and worth the development effort/cost.  
(Version 5.5)

SANDRIFT  I am a Mars scientist, and I can confirm that many of us do prefer Macs; it's not at all uncommon to see as many Macs as (or more than) PCs at professional meetings. See my reply to the next comment down as to the utility of this expenditure of tax dollars...  
(Version 5.5)