Abstract
Umigon is developed since December 2012 as a web application providing a service of sentiment detection in tweets. It has been designed to be fast and calable. Umigon also provides indications for additional semantic features present in the tweets, such as time indications or markers of subjectivity. Umigon is in continuous development, it can be tried freely at www.umigon.com. Its code is open sourced at:https://github.com/seinecle/Umigon.