Just to explain
JaWi's answer a little better...
- http://perlmonks.thepen.com/ is a mirror of perlmonks.org designed to be more search engine friendly.
- URLs such as http://perlmonks.thepen.com/dlcode/41961.txt provide direct access towhatever people submit as the "code" attached to a node (in this case, Node Id #41961)
- Anytime you have a Node Id for perlmonks, you can go to http://perlmonks.org and enter the Node Id (41961) in the search box, to see the complete information on that node (including author, posting date, replies, etc...) from the live site.
In the future, if someone suggests that one of your students was plagarizing code from a PerlMonks URL, but page is served by thepen.com, just look for the nodeId.