aeternitas (rubygems):     Æternitas provides means to regularly 'poll' resources (i.e. a website, twitter feed or API) and to permanently     store retrieved results. By default æternitas avoids putting too much load on external servers and stores raw     results as compressed files on disk. It can be configured to a wide variety of polling strategies (e.g. frequencies,     cooldown periods, ignoring exceptions, deactivating resources, ...)." 
Keywords: continuos-data-retrieval|ruby-gem|ruby-on-rails