Run a virtual conference using only open source tools

I have helped run three virtual conferences in the last eighteen months, all on a tight budget, and every one of them used a free and open-source software stack end to end. The total cost was about $80 per event: a domain name and a few hours of staging on a $5 VPS (Virtual Private Server, a small rented Linux machine you can SSH into). If you are organizing a community conference, a regional meetup, or a company-internal event and the budget does not allow Zoom Webinars, the open-source path is real, it works, and it is not that hard to set up. Here is what I learned and what I would tell a past version of me who was staring at a $4,000 Zoom quote.

The pieces you actually need

A virtual conference is not one thing. It is a stack of small tools glued together:

• A streaming server that takes a presenter’s webcam and audio and turns it into a stream viewers can watch. Jitsi Meet (an open-source video conferencing platform) and BigBlueButton (an open-source web conferencing system built for teaching and events) both work for a single speaker. For multi-track events, OBS Studio (Open Broadcaster Software, an open-source tool for capturing and streaming live video) to a media server like OvenMediaEngine or Janus Gateway (both open-source WebRTC servers that handle real-time media routing) is the way to go.
• A schedule and a place to put talk recordings. Pretalx (an open-source conference management tool that handles call-for-papers, scheduling, and speaker coordination) handles the schedule, the call-for-papers, and the speaker portal. After the event, the recordings live on a PeerTube instance (PeerTube is a federated open-source video hosting platform, an alternative to YouTube) or a plain old web server.
• A chat for attendees. Matrix (an open standard and set of servers for federated real-time chat) with the Element web client is the obvious choice. Most of your audience already has a Discord or Slack account, so the bar is “does it work in a browser without an install.” Element does.
• A way to take questions. Most conferences use a separate Q&A tool. For our events we used the Matrix rooms directly, with a dedicated room per talk. Speakers answered live in the room after the talk.

That is the full stack. Every piece is open source, every piece can be self-hosted on a small VPS, and every piece has a hosted version if you would rather not run it yourself.

What I would not skip

The single most important piece, and the one most people skip, is the rehearsal. Run the presenters through the stack the week before the event. Have them join the video call, share their screen, and stream to the same media server you will use on the day. Most issues that show up during a live event are issues that would have shown up during rehearsal and that you would have fixed in thirty minutes.

Second, record everything locally on the presenter’s machine as a backup. OBS can do this with a single checkbox. If your media server goes down, or if the presenter’s network drops, you still have a clean recording that you can post-process and publish after the event.

Third, write a one-page attendee guide. “How to join, how to ask a question, how to report a problem.” Send it by email the day before, link it from the conference website, and pin it in the chat. The single biggest source of attendee frustration at our first event was people not knowing which room the next talk was in.

The trade-offs you should expect

The biggest honest cost is the operator time. A free software stack does not have a “support team you can call.” When something breaks, you fix it. For our first event, that was me at 6 AM on a Saturday, debugging a misconfigured TURN server (TURN is a protocol for relaying real-time media when direct peer-to-peer connections fail, often blocked by corporate firewalls) because one of the presenters was behind a corporate firewall that blocked WebRTC. I figured it out in forty minutes, but it was a real forty minutes I was spending on a Saturday morning.

Production polish is the next cost to think about. BigBlueButton and Jitsi look good. They are not “looks like a Netflix production” good. If you are running a corporate event with a $50,000 budget and an audience that expects a TV-style production, the open-source path is going to disappoint. If you are running a community event, a regional meetup, or an internal company session where the audience cares more about the content than the production, the production gap does not matter.

Discovery is the third honest cost. A free and open-source conference platform does not show up on a Google search. Attendees find the event by being told about it. If your usual marketing channels are weak, the switch to open source is going to be doubly painful because the marketing problem did not get solved by the platform switch. This was true before the switch, and it is true after.

A stack I would actually use today

For a single-track community event with up to 200 attendees:

• BigBlueButton for the main room, hosted on a small VPS or a free Greenlight account if you do not want to run it yourself.
• Matrix (Element Cloud if you do not want to self-host) for chat, with a separate room per talk.
• PeerTube for talk recordings, hosted on the same VPS.
• Pretalx for the schedule and call-for-papers. Pretalx Cloud is free for events under a certain size; self-hosting is straightforward on the same VPS.
• A static site for the conference website. A Jekyll or Hugo site deployed to Netlify or a $5 VPS handles the program, the schedule, and the speaker bios.

For a multi-track event, the only real change is replacing BigBlueButton with an OBS + OvenMediaEngine setup, which is its own substantial configuration task. I would only do that if the budget was tight and the operator team was comfortable with WebRTC. If the operator team is not comfortable, hire it out or use a hosted solution for the media side and keep the rest open source.

Bottom line

If you are running a community event on a budget, the open-source stack works. The cost is operator time, the production polish is a step below the commercial options, and the marketing problem is yours to solve. For a first-time organizer, the path of least resistance is BigBlueButton + Element + Pretalx, all on free hosted tiers if you do not want to self-host. For a returning organizer who is comfortable with a Linux server, the self-hosted version of the same stack is $5 a month and a few hours of setup.

If I could send a message to past me who was staring at a $4,000 Zoom quote, I would say three things:

• The free path is real. It is not a hack, it is not a workaround. It is the same software many universities and government agencies use for the same job.
• The operator time is the real cost. Budget a Saturday for setup, a Sunday for a full dress rehearsal, and a Monday for the event itself.
• The production gap is fine. Most of your audience is not going to notice that your media server is a $5 VPS running Nginx (a popular open-source web server, often used as a reverse proxy to front-end other services). They are going to notice that the talk was good.