LimeWire Pirate Edition is based on LW 5.6 beta. Some persons prefer LW version 4. We provide links to LW 5 & 4 versions on the forum so it's up to you which you choose.
http://www.gnutellaforums.com/340213-post427.html
As for viruses, if you are a Windows user, you should check all downloaded files with a virus checker.
LW 5 did have AVG built into it, but that stopped working 2-3 months after the LW company stopped distributing their software. The AVG company probably decided to close the connection link from LW 5 users for virus definition updates. (Unless the link passed through the LW offices first, in which case it would have been LW company who turned the switch off.)