Complex sentence: Perihelion Software also produced an in-memory database system called Polyhedra; the group responsible for this product was set up as a subsidiary (Perihelion Technology Limited) which did a management buyout in 1994.
Split into simpler sentences: Perihelion Software also produced an in-memory database system called Polyhedra. The group responsible for this product was set up as a subsidiary, Perihelion Technology Limited (PTL), which did a management buyout in 1994.