Several people have asked for an OpenID library for Classic ASP. Yes, it's several years deprecated, but there are still some major and smaller sites using it. Classic ASP allows the consumption of COM/ActiveX objects, so it turns out DotNetOpenId can be used by Classic ASP!
But DotNetOpenId isn't a COM server. Not in its released form anyway. But there is now a CTP of DotNetOpenId that does offer a COM interface that Classic ASP can call into, and it includes an actual sample of a classic ASP OpenID relying party.