Languages like Ruby, Python, JavaScript and LuaJIT can’t call C directly, but they do support FFI. The bindings for these languages work rather like C++, but use FFI to call into libvips and run operations.

Since these languages are dynamic, they can add another trick: they intercept the method-missing hook and attempt to run any method calls not implemented by the Image class as libvips operators. This makes these bindings self-writing: they only contain a small amount of code and just expose everything they find in the libvips class hierarchy.