Travolutionary - Travolutionary is an aggregation, reservation and distribution platform by Gimmonix, with access to hundreds of travel inventory providers across hotel, air, car and content.
Baïkal - Cal and CardDAV server
Eventric - Eventric is an professional tour management solution.
Radicale - The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.
Xola - Xola is an elegant and powerful online booking and distribution system. We help tour and activity providers reduce costs, grow revenue, and save time.
DAViCal - DAViCal is a server for calendar sharing.