indico
Feature-rich event management system, made @ CERN, the place where the Web was born.
Self-hosted Conference Management software
Software for submission of abstracts and preparation/management of academic conferences.
5 apps, ranked by GitHub stars weighted by maintenance health.
pretalx
Web-based event management, including running a Call for Papers, reviewing submissions, and scheduling talks. Exports and imports for various related tools.
OpenSlides
Presentation and assembly system for managing and projecting agenda, motions and elections of an assembly.
osem
Event management tailored to free Software conferences.
motion.tools (Antragsgrün)
Manage motions and amendments for (political) conventions.