AllDibs

AllDibs is a shared booking calendar for anything a group owns together but only one person can use at a time: a family cabin or lake house, a boat, a campervan, a spare room, or the tools in a neighborhood tool library.

Whoever hosts an item gives every member a budget of midweek and weekend credits. Booking a day spends a credit, overlapping bookings are refused, and the credit comes back on its own once the day has passed. Nobody has to police the calendar, and the person who used to claim every summer weekend no longer can.

Every item has unlimited members, co-hosts, a message thread, and room for photos and files such as the manual or the launch checklist. Members join by invite link. The first five items are free, and more come in one-time blocks with no subscription. It runs in the browser on any device, so there is nothing to install.