connpass is an IT meetup and event platform used by engineering communities to plan gatherings and recruit attendees. Organizers can publish event pages, define several attendee types and application periods, add questionnaires and co-organizers, and choose first-come or lottery-based registration. They can manage applicants, send reminders, and collect presentation materials. Attendees can search events, apply or join a waitlist, bookmark events, follow groups for updates, and review shared slides after a meetup. The service works on PC and mobile. Official guidance says registration and use of connpass are free, although an organizer may charge an event fee; connpass says it adds no fee to prepaid payments beyond PayPal's own charge.