nsrlsvr is a tool to facilitate looking up data in the National Software Reference Library (NSRL). It's in a 1.1 state, which means it's unlikely to break in two if you look at it the wrong way but still may not be as stable as you'd like.
Installation instructions are found in the INSTALL file. Please read them. Due to the size of the NSRL's reference data set (RDS), installing nsrlsvr is a little bit more involved than one would like. It isn't hard: it's just not quite a configure, make, make install dance.