Does control-desk software need installing?

No. Everything happens in the browser, including for guests, who only have a link to open.

Which platforms can it stream to?

Those accepting an RTMP stream, which covers the common video platforms. The relay is set once.

Yes: the run of show sends them one after another, opening the incoming one and closing the previous, without republishing the page.

A broadcast composed in the browser, guests by link, a room that votes, then the replay.

Illustration - no real data

The only format where video is the heart: everything else organises around it.

Before
You build a registration page, participants get their link, and you prepare the run of show: the polls in the order you will send them. The control desk is set up in advance: sources, lower thirds, guests.
During
You compose the broadcast in the browser: camera, screen share, guests joining by a link, grid or picture-in-picture. Meanwhile the room votes, asks its questions, and the interactive block changes poll without the page being republished.
After
The replay is published on the site, with its visibility. You read time present, referrers, and send the report.

Four modules carry most of a webinar. The Studio comes first.

Two things a webinar sometimes needs and the tool does not do.

No video editing: the replay is published as you provide it, by its address or as a file of up to 200 MB.
No automatic failover if the network drops. A broadcast depends on the connection of whoever runs the desk, so plan for it.

Does control-desk software need installing?: No. Everything happens in the browser, including for guests, who only have a link to open.
Which platforms can it stream to?: Those accepting an RTMP stream, which covers the common video platforms. The relay is set once.
Can several polls be chained during the broadcast?: Yes: the run of show sends them one after another, opening the incoming one and closing the previous, without republishing the page.