Resource Availability / Reservation / Booking Modules

Several projects handle scheduling reservations for a scarce resource— a conference room, a tee time, a dinner table.

See also Comparison of Booking System modules.

Active Booking (& related) Projects

http://drupal.org/project/agreservations (Agreservations)
http://drupal.org/project/availability (Availability)
http://drupal.org/project/airplane_reservation (Airplane Reservation System)
http://drupal.org/project/bat (A generic framework for building any type of booking solution from hotels to conference rooms to boats, etc)
http://drupal.org/project/bee (BEE is a D8 module based on BAT that allows you to add booking & availability functionality to any node type)
http://drupal.org/project/bookingsapi (Bookings API)
http://drupal.org/project/booking_timeslots (Booking Timeslots)
http://drupal.org/project/checkfront (Checkfront)
http://drupal.org/project/merci (MERCI: Manage Equipment Reservations, Checkout and Inventory)
http://drupal.org/project/planyo_reservation_system (Planyo)
http://drupal.org/project/publicbookings (Public Bookings)
http://drupal.org/project/reservation (Reservation)
http://drupal.org/project/reservations (Reservations; originally based on OpenResort)
http://drupal.org/project/resource_booking (Resource Bookings)
http://drupal.org/project/resource_conflict (Resource Conflict)
http://drupal.org/project/simple_reservation (Simple Reservation)
http://drupal.org/project/uc_hotel (Hotel Booking System for Ubercart)
https://drupal.org/project/rooms (Hotel room booking and management)

Dead / Inactive

http://drupal.org/project/bookings (Booking System API)
http://drupal.org/project/mrbs (MRBS; integration of http://mrbs.sourceforge.net/)
http://drupal.org/project/openresort (Open Resort community Edition; integration of http://www.openresort.org/ )

Other

http://drupal.org/node/805048 (pending eventbookings module)
http://resmania.com/ (ResMania service, claims Drupal integration)

See also ...

http://drupal.org/project/availability_calendars (Availability Calendars)
http://groups.drupal.org/booking-systems
http://groups.drupal.org/travel