I'm developing a stand-alone, cross-platform desktop app for Windows, Mac, and GNU/Linux. I've read these (, ) questions and concluded that I'll have to cherry pick guidelines from all three HIGs as the end-users span across the three platforms with Mac users > Windows Users >> GNU/Linux users. I was thinking about using a platform-agnostic HIG, but struggled to find modern ones. The most complete one I found was this archaic style guide for WxWidgets from 2006.
While being very old, a lot of the guidelines still hold true 15+ years later. Does it make sense to follow this guide or is that ridiculous?