When I visit Unix & Linux, I can barely tell when someone has included a hyperlink. Just today I could tell from context that a user had included a link in the answer, but until hovering over it with my mouse I wasn't sure which word(s) were part of the hyperlink.
The contrast is pretty poor in Chrome, but reasonably bad in Firefox and Internet Explorer. For me it gets even worse when I'm not facing the screen exactly straight; even the difference between my eye level and the top of the screen makes it noticeably more difficult to distinguish between normal text and hyperlinks.
I realize that this question already discusses this topic in general across all Stack Exchange sites (and this one asks in a really vague way), but I wanted to bring this up in the context of Unix & Linux specifically since that's the place where it's been the biggest issue for me. I've never had too much of an issue on other Stack Exchange sites.
P.S. I'm currently on Windows 7 if that makes a difference.