Graphene is a product of Cryptonomex used in BitShares, MUSE, Identabit, and possibly Play.
We also offer it for use in private blockchains for our commercial customers.
There are many different business models that can be implemented using Graphene, one of which is BitShares.
So it would not be correct to say that the others are derived from BitShares.
Graphene is a superset. It is a blockchain operating system, while BitShares is just one thing you can build with it.
BitShares doesn't need to use the Graphene name in its marketing, but Cryptonomex does.