If an assembly needs motions, amendments, speaker lists, and secret ballots on one shared screen, OpenSlides is the open-source web application that runs them. Before the meeting, administrators set up committees and meetings, import participants from CSV or connect a SAML identity provider for single sign-on, email invitations with login data, and sort people into groups with freely defined rights. Members file motions in an HTML editor, attach documents, gather supporters, and send them through customizable workflows with automatic numbering by category, and amendments and change recommendations attach to specific line numbers. Motions can be forwarded to other meetings. During the session the agenda reorders by drag and drop, and every item, motion, or election gets its own speaker list with countdowns, points of order, and recorded speaking time. Votes are open, secret, or nominal and run live for present participants in voting groups, with proxy delegation, vote weighting, multiple rounds, and Yes/No/Abstain options per candidate or list. Results appear against a chosen reference value on projectors, in PDF exports, or as individual tallies. Several projectors can show the current item, a lower third for the active speaker, and live results, and Autopilot guides participants through whatever is happening. A video livestream brings in remote attendees. Afterward, motions export to PDF, CSV, or XLSX. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.