
It seems that Shinano Kenshi, the company that developed Plextools (see also Kenshin's information in the CDFreaks thread), is now asking Alex and zeb_ (who is responsible for a Linux port of these tools) to remove the project from the various sites.
There's a thread at CDFreaks dedicated to this discussion.
Personally, I don't have a Plextor drive, but PxTools are so much better than Plextor's efforts that this attempt at muzzling open source support removes any incentive I'd have to buy one.
Shame on you, Plextor!

G