I've started a converter for Fantasy Grounds. It takes the JSON of a character and creates the XML that can then be imported into FG. It only does basic things right now. Skills, Abilities, personal information (homeworld, name, gender, etc.)
You can find my code here:
https://github.com/BoomerET/hlosf2fg
At this moment, I'm thinking of moving over to the API. Looking at docs.
Dave