suacomp is a small library, which overlays the SUA libc. It wraps a whole lot of functionality from the original libc, handling common problems that have shown up in over two years of porting various software to interix (including, but no limited to, libX11, openssh, etc.).
I hope that it will be useful to others too.
Note: New Gentoo Prefix for Windows releases will have this library built-in already by default.