Who is the oldest CAD vendor still operating? My guess is Intergraph (originally named M&S Computing), based in Huntsville Alabama. Its first product was real-time software for NASA, sometime in the 1960s -- which makes it at least 40 years old.
Who is the longest serving employee in CAD? That might belong to the staff at ACS Software, who have been there since the company's beginning in 1981. Debbie Simpson of ACS sent a press release yesterday with this footer:
Did you know that 2009 marks ACS Software's 28th year in business?! That's right, ACS has been around since 1981 -- one year before Autodesk opened their doors.
ACS Software develops the AutoEDMS Document Management & Workflow Solution for workgroups, and they just released the SR4 update for v6.5.