software cad name san or sun on unix platforms

[Kaji]

Save work at a design office and today a collaborator asked if we knew someone who could open and convert old drawings made with a software that he called "san" and that turned on unix platforms, I ask if someone ever heard of it and could give me some more information about it.
thanks for availability

 

[nicksoft]

cad programs don't come to mind, it's not that it refers to workstations "sun microsystems?
Do you know more about these files, such as extension?