[goldfire]

> Unfortunately the Windows syscalls are not officially documented and even less stable than on Linux, changing even between service packs.

You can get pretty close though; it's possible to skip the C runtime and most of the other user space libraries and call into ntdll directly. Many of the functions it exports are fairly thin wrappers over the system calls.

[int_19h]

ntdll.dll is still not a stable API - if you use anything exported from it (excepting a few documented ones), you basically have zero guarantee that your app will still be working with the next Windows update.