5.4 was the first version of
UBB.threads. Prior to that it was WWWthreads. If it's earlier than 5.2 then it was Perl. All of the old versions included an upgrading doc with the software, so they'd just need to follow those instructions to get up to version 5.4, at which point the 6.5.5 version has everything they need to get upgraded at that point to prepare for the import.
It's a lot of upgrade steps, but definitely possible
