Here's an archive of the link:
archive from 2005
The link says that the JDL had been "deemed" a terrorist organization, but it is unknown whether it is. It does state that it is a violent extremist right-wing organization though. And yet it does note that the single act of terror known to be planned by its members had been averted. It states that the act was designated as an isolated incident. The organization itself does not have a "terrorist" designation.
The distinction between being designated a terrorist organization and not being one is quite significant. Having such a designation would make it illegal to donate money to any of organization's causes. It would also make it impossible for the organization to engage in regular banking transactions.
As a comment on the question itself, the link you referred to is not a list of terrorist organizations, but rather of known terrorist activities. It does distinguish between organizational vs individual activities.