This is what I've been able to gather:

There are two implementations of the standard C++ library available on OS X: `libstdc++` and [`libc++`][1].  They are not binary compatible and `libMLi3` requires `libstdc++`.

On 10.8 and earlier `libstdc++` is chosen by default, on 10.9 `libc++` is chosen by default.  To ensure compatibility with `libMLi3`, we need to choose `libstdc++` manually.

To do this, remove `-lstdc++` from the linking command and add `-stdlib=libstdc++` instead.