The Expat 2.0.1 Makefile.in template file does not contain support for the autoconf EXEEXT macro variable. I've attached a unidiff that adds this support. No changes to the configure script are required; the necessary logic is already present. I've tested these changes on a Stratus VOS system, which has a required executable extension. The changes are harmless on an operating system that does not require such an extension. Thanks for your consideration of this patch.