Dudle - Dudle is an online scheduling application, which is free and open source.
FinancialForce HCM - FinancialForce.com provides cloud back-office applications for Salesforce CRM.
Pulse 24/7 - Booking & scheduling mobile app for service providers
StarGarden HCM - StarGarden HCM is an integrated HR and Payroll software with workflow automation tools.
Time Slot Booking Calendar PHP - Time Slots Booking Calendar PHP for online appointment booking and class scheduling.
Vibe HCM - Vibe HCM is a recruiting and employee engagement platform.