The 2019 edition of the week-long Awesome Games Done Quick, the world's largest speedrunning event, is now live. The first day includes runs of Hollow Knight, Serious Sam Classic: The First Encounter and a Portal race. You can watch all of them on the Games Done Quick Twitch channel (or in the player above)—after a short pre-show, it'll launch straight into speedruns.
The event is raising money for the Prevent Cancer Foundation, and will run 24 hours a day for a full seven days, wrapping up in the early hours of next Sunday.
The full schedule is here: it tells you which game is being run, the name of the runner, the estimated length of each run, and how long they take to setup. I usually stick it on in the background if I'm near my laptop, and then dip in when there's a run I'm particularly keen on. I'm a fan of co-op speedruns and, this year, there's more co-op runs than ever, so I'll definitely be watching whenever I can.
If you want more information, check out the Games Done Quick website.