Zoom was founded in 2011, and they've had incredible growth since launching. Zoom is mainly known as a meetings platform, not a webinar platform. It's reliable, stable, and has great stream quality, and these features work really well for meetings. However, as a webinar platform, it's lacking quite a few marketing features, deep integrations, and it also requires a download for all attendees.
BigMarker was founded in 2010 as a web conferencing tool for training, education, and more. Later on, they started adding more marketing and engagement features. They also offer meeting and conference rooms.
BigMarker serves a lot of universities, and they offer a variety of white label services to completely custom brand their platform to match any company's branding.