OT - CAD question

[James Pifer]

I have some drawings an architect did for me that I would like to open
in some CAD program and hopefully make some modifications. The catch is
the architect did the drawings in Softcad (I believe version 11). My
understanding in that this version could not export to dwg. 

The files he sent me have an spd extension. Anyone know of any way of
getting these opened or converted to another format? Any CAD program on
Linux be able to open them? Right now I have no specific CAD program
running on my Redhat or Fedora machines. A "free" one would be
preferable. 

Being an off topic question replies can be sent to me directly if anyone
has any ideas. 

Thanks,
James