GoToWebinar is one of the major webinar softwares in the space in terms of market share. Originally founded in 2006, it still maintains a lot of the same design elements that were used over 10 years ago.
GoToWebinar provides a webcast version of their software, but the majority of events are run with the standard downloaded version.
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.