This is not a complete answer. Enhanced Ground Proximity Warning System was conceived and patented by Honeywell, nee Allied Signal-Bendix, nee Sundstrand Data Control. Sundstrand patented the original GPWS in about 1976, reportedly upon stealing the idea from SAS engineers.
Bendix, Collins and Litton also built GPWS computers in the mid-late 1970s until stopped for patent infringement. They were allowed to continue supplying existing customers. It didn't take long for the price of a GPWS computer to go from $4K to $25K, of course.
Terrain Alert and Warning System was the name adopted by the FAA, at least partly to avoid automatic association with a single manufacturer. Yes, there are different schemes and presentations and levels of sophistication. I'm sure someone else can inform us.
GB