spinoff
An offshoot.
An incidental benefit or unexpected pay-off.
Space research often provides a spin-off for everyday technology.
By-product.
A fictional work where the protagonist was introduced in a preceding work or at least shares the same setting, often in a different aspect.
"Frasier" was a spin-off from the sitcom "Cheers".
The formation of a subsidiary company that continues the operations of part of the parent company; the company so formed.