FOSS alternative to Counterpoint?

[Richard Jeroloman]

"Counterpoint" is an old DOS based inventory control program for large retail 
businesses.  One of my retail clients is using it to manage $1,200,000. in 
inventory and I'm about to recommend that they get something more up to date.  
I hate to see them spend a lot of money on an MS Windows based program.  Does 
anyone know of a FOSS equivalent?
                       Terry