Hello, just wanna tell you that i adopted NativeBoost under Cog and have a first running prototype. It still lacks callbacks support, but its already can be used for callouts and to run native code. NativeBoost-CogPlugin does not requires patched for platform-specific code. Just load it into Cog VMMaker image, generate & build vm and you done! Thanks Eliot for providing necessary bits for controlling memory execution protection. The NativeBoost-CogPlugin will have some additional functionality, comparing to its Squeak VM cousin. - it using a primitive failure codes, so when primitive fails , you can determine why and where your native call fails. The primitive error codes still not handled/used by language side, so its a work to do: - a marchalling code can use error codes to report that primitive fails due to coercion error, and it even will tell which exactly argument failed to coerce. - of course, you will be able to add own custom error codes, and handle them as you like to. By default, a plugin could report following problems: "execution of native code is not enabled by plugin" ErrNotEnabled "failed to find a native code for primitive method" ErrNoNativeCodeInMethod "native code generated for different platform" ErrInvalidPlatformId I wanna say thanks to Eliot for providing primitive fail codes in VM. A proper error handling is an important part of infrastructure-level project (such as NativeBoost), since then people who using it, can quickly determine what's wrong with their code. -- Best regards, Igor Stasenko AKA sig.