Acre was Google/Metaweb/freebase.com's hosted serverside-javascript application environment. It closed March 31, 2014.
Acre was a free, hosted application environment which allowed applications to be written in server-side Javascript and a templating language. It was developed by Metaweb, later acquired by Google, and was shut down by Google on March 31, 2014. Apps with a permanent URL were hosted on the freebaseapps.com domain, e.g. http://split.freebaseapps.com/
Google maintains a wiki on Acre.
Acre elements are available on freebase at /freebase/apps