That API allows you, from Delphi to compile C99 sources, or load in precompiled sources at runtime. As such, you have access to a lot of C99 libraries you can now, with ease take advantage of. It's small and fast, so it can be used as a scripting solution if you wish. You have access to the symbols, so code and data can be exchanged between Delphi and C. There are examples in the distro that demonstrates all these features. Think of it like using Lua from Delphi, it's just easier, cooler much more powerful. It leverages Tiny C Compiler for the backend code generation.