Gitlab is a pioneer here. The did start with the 2000 minutes free of shared runners, for private and public repos. I really think we should all thank them for pushing ahead on innovation.
Gitlab invented this, github copied.
Same as Snapchat invented, Instagram copied them.
I don't know about the timeline between when Gitlab CI started vs Travis, and gitlab certainly made the innovation of integrating it into the code host, but certainly Travis and Circle CI were popular before Gitlab was.
Gitlab invented this, github copied. Same as Snapchat invented, Instagram copied them.