This deep dive explores alf.io, an open-source event ticketing and attendance management system designed for organizers prioritizing privacy, security, and fair pricing. Unlike commercial platforms, alf.io offers organizers true control over their event and attendee data, with a philosophy of freedom rather than just being free of charge. While the software itself is free to use and modify, running it requires resources, necessitating financial contributions or sponsorships to maintain its development and stability. Alf.io ensures security through HTTPS and strict content security policies, and simplifies PCI compliance by integrating with major payment gateways like Stripe and Mali, ensuring sensitive card data is never stored on the organizer’s server. The system is modular, featuring a core web application with a public ticket shop and an admin back office, and supports multiple languages. Payment flexibility is a key feature, accommodating various global and regional payment methods, including bank transfers and on-site payments. For analytics, alf.io collects anonymized statistics with scrambled IP addresses to comply with GDPR, and the core developers do not receive any usage data. For event check-in, alf.io offers two tools: the mobile app Alf.io Scan for smaller tasks and the robust Alf.io-PI system, built on Raspberry Pi for high-throughput, offline-capable check-in stations that maintain data integrity. For those who prefer a hands-off approach, Swicket offers a premium managed hosting service for alf.io, providing convenience and dedicated support. Ultimately, alf.io presents a compelling alternative to commercial ticketing platforms by empowering organizers with control, enhancing attendee trust through data privacy, and fostering a more direct relationship between organizers and their audience.