arc90, inc. 747 3rd Avenue, 30th Floor New York, NY 10017 Tel: 212.400.6296 arc90 is an experienced team of design and technology professionals. We are passionate about creating groundbreaking, compelling web/software experiences. Yammer API Client LibraryYammer is a new microblogging service that has been described as "an enterprise version of Twitter". Instead of asking, "What are you doing?"