Weird Island

Leafing through the newspaper one morning you come across a notice requesting your presence at 'HUGH, PUGH and BARNEY-MAGREW Solicitors to Elizabeth Taylor.' Puzzled (and who wouldn't be), the next day you visit the solicitors where you are told that you have come into possession of a remote island paradise. The island was apparently claimed by five galley slaves many, many years ago; one of whom was your ancestor (its nice to know who your descended from).
Ownership of the island passes between the families of the founders every 100 years and your family is next in line to do with the island what you wish. You were supposed to be told this by the previous owner of the island but he seems to have conveniently disappeared. Anyway, the solicitors suggest you go out to the island to see for yourself. Strangely, you feel happy to oblige...

What is abandonware ?