An example Makefile is included with the NDK examples shipped in the NDK sub-directory of the Documentation installed with NUKE.
For OS X, plugins will need to be built with GCC 4.0 in order to be compatible. The use of GCC 4.2 or LLVM is unlikely to produce compatible plugins. It is also required to use the 10.6 SDK to build plugins.
If you want to build with the Intel compiler, just substitute it for g++ in your makefile, however you must make sure you use the libstdc++ includes and libs from the GCC 4.0 install in order to be compatible.
On Mac OS X, NUKE is built on Snow Leopard, using GCC 4.0. We recommend third-party developers to do the same.
Warning
If you build on newer versions of Mac OS X, they are not usually compatible with older versions, regardless of which version of the OS X libs you actually build/link against.
The resulting shared object file (.dylib) should then be moved to your ~/.nuke directory (or otherwise into the NUKE plugin_path).
See Building & Installing Plug-ins for information on creating your first plug-in.