MD5SUM usage?

["Xu, Qiang (XSSC SGP)" <Xu Qiang xssc sgp xerox com>]

Hi, all: 
In the source page of MC, there is always a file MD5SUM. I guess it is used
to do checksum after downloading the source file (for example:
mc-4.6.0.tar.gz) to confirm dowloading is completed without error. 
But how can I do the check? I haven't had such experience. 
Anyone can tell me how to do the checksum using MD5SUM? 

thanks, 

Regards,
Xu Qiang