Well, I'd mainly written it for people who were (already) asking me about how we differed from other integrations or why we did what we did ...

LDC (D with LLVM) is written in C++, so they invoke LLVM APIs, but I don't know what they generate (bitcode or machine code).

Julia is written in C++, they invoke LLVM APIs, they call the JIT.

CLASP is written in C++ and Common Lisp, they invoke LLVM APIs, but I'm not sure if they only JIT or if he stores anything to disk yet.

And so on ...

I like the C++ ABI though it is in constant flux. The C API is stable but just too limited. Generating bitcode yourself is probably a pretty good strategy too, if your library is good.