The links on pluck-cms.org's demo site are broken. Updated links:
OSCMS page on Pluck: http://php.opensourcecms.com/scripts/de … name=Pluck
OSCMS demo index: http://www.opensourcecms.com/demo/1/169/Pluck
OSCMS demo admin: http://www.opensourcecms.com/demo/2/169/Pluck
The View Site link in the admin section provides a link that bypasses the ads, though I don't know the legality of bypassing them so I'm not going to directly post links.
I hope this helps!