Indico is an open source content management system developed at the European Organization for Nuclear Research (CERN) and currently used in more than 90 scientific institutions world-wide. Indico provides a multitude of features to conference/meeting organizers, merging the capabilities of a powerful CMS with a calendaring layer, thus allowing users to keep track of past and future meetings, and to quickly access all the resources concerning a particular event. Other very useful features include:
At CERN alone, Indico serves a community of around 10.000 users, with ~15.000 different visitors per day (~1 M hits). It hosts more than 150.000 events, made of around 700.000 individual contributions/talks and ~900.000 files. It has become part of "CERN speech" - "look it up on Indico" is almost as obvious as "Google it" around here.
But Indico is as well an indispensable tool in the realm of High Energy Physics, going far beyond the borders of this organization. Institutions such as Fermilab, MIT and IHEP (China) are using it for their own meetings/conferences.