This is just 1 link to split designs(appliq. fonts) if you Google split fonts you will find other links. I have used these particular ones to make Garden Flags/Lillian
For these kind, No you do not need special software/Lillian
If you mean splitting a design that's too big for your hoop a basic customising programme can do that for you, either automatically or manually.
If you mean a design split in two to Get an area to add a name or sentiment you would need digitising software. See link explaining how to do that.
You can use the free trial of Embird
Are you wanting to digitize them yourself or are you wanting to know just about stitching them out?
I don't know the answer to your question, but you are asking in the right place!