Rainlendar - Rainlendar - Customizable desktop calendar
Qloapps - Open Source System - Build Hotel Booking Website and Manage Online & On-Desk Bookings.
Fantastical 2 - Fantastical, the Mac calendar app you'll enjoy using. Quickly create new events with natural language input and more.
FewohBee - Web based management tool for hotels, pensions, accommodations and vacation homes
Date Reminder - Date Reminder reminds you of recurring or nonrecurring events, like birthdays, bills to pay...
BSI Hotel Booking System - BSI Hotel Booking System is a real time online hotel booking.