What are the advantages of using betterC?

[Adam D. Ruppe]

betterC is a niche restricted feature set. If you don't already 
have a use case in mind, I'd recommend avoiding it.

It is for cases where you're stuck with certain limitations to 
integrate with the outside world. Like running on peculiar 
hardware or interoperating with certain outside programs where 
you can't initialize the runtime properly (and even then, you 
might be better off going with a custom minimal runtime over the 
betterC prepackaged restrictions).

Some libraries try to be compatible with it so they can be used 
in those special cases too, but you probably don't need it.