Program: Trader's Little Helper
License: Freeware (can't seem to find a license file, so I'm not sure about the particulars)
Description: Although many free/portable audio conversion tools exist (and at least one exists on PA), this particular tool can handle formats that others cannot. For example, .shn files. These are files most commonly found amongst bootleg/live recording communities, which you can often find on the Internet Archive's live recordings section.
Thanks for your time!