Over on Re: How Xerces validation access http schemas ?, hippo wrote "It's worth noting that the most recent versions of XML::Validate and XML::Xerces are from 15 years ago and may not play so well with modern systems". This immediately reminded me of a recent search for modules to connect with PayPal where I found Business::PayPal::IPN but didn't look any further than the date which is AUG 19, 2003.
Clearly for things that connect to frequently evolving APIs, being quite up to date is pretty important unless the API allows use of a particular past version. But for things that don't change much, like XML, the need for recent updates is less apparent. As hippo puts it, they need to "play well with modern systems".
So, when deciding whether to use a module, or anything else for that matter, how old is too old?