I'm not sure what WINDOWS means. And I'm not sure MSFT knows either :) Less flippantly, the goal is that OPENSSL_SYS_WINDOWS means any Windows platform, and then there are subtypes within that. We'll figure it out as we go along. It's gonna take a while to clean up the #ifdef world without breaking folks, but we're trying to address it per our roadmap, https://www.openssl.org/about/roadmap.html .
/r$ -- Principal Security Engineer Akamai Technologies, Cambridge MA IM: rs...@jabber.me Twitter: RichSalz