Yammer-notifier is a project mainly written in Ruby, it's free.
Sample ruby code to share information on Yammer.
=== Dependencies: gem install yammer4r
=== To get up and running
Basically you need to generate an oauth.yam file so you can run notifyammer.rb script.
1) Download script: curl -O https://github.com/jpatterson/yammer4r/blob/master/bin/yammer_create_oauth_yml.rb
2) Create your yammer app https://www.yammer.com/client_applications/new
3) Have with you consumer key and secret
4) Run yammer_create_oauth_yml.rb script, that will generate a oauth.yam file
5) Now you are ready to play with notifyammer.rb