"The Compleat Works of William Shakespeare (Abridged)" is a play not in the public domain, by Adam Long, Daniel Singer, and Jess Winfield and available through Broadway Play Publishing (and a fantastic show, a true crowd pleaser... they're still talking about it around here). The works of the Bard himself are in the public domain, however, adaptations of the text may not be... it depends on the source of the script.

Lets carry the discussion a little further - how can we tell if something is in the public domain? Things that come to mind are Spoon River Anthologies, The Wild Party, G.B. Shaw, etc. I have looked at Project Gutenberg and it LOOKS like they only include material in the public domain but they never say yes or no. I have also heard that copyrights expire 50 years after the death of the author. Is there a sure fire way to tell?

According to the Library of Congress, the copyright becomes public domain 75 years after the author's death UNLESS it is renewed by an estate, a new owner, etc.

But how exactly would one go about finding out if a copyright had been renewed? The Library of Congress and the Copyright office can be very helpful, but only in American Circles. Is there a British counterpart, for example?