One design language that I really like is the Atlassian/Bitbucket one.
https://atlassian.design/guidelines/brand/color-1
I've generally really liked the changes to bitbucket over the last few years in terms of UI and UX.
They also have an impressive component archive.
https://atlaskit.atlassian.com/packages
A lot of the packages are under an Apache 2 license, I can't say all as I haven't looked but the master repo is Apache 2.0 as well.
One design language that I really like is the Atlassian/Bitbucket one.
https://atlassian.design/guidelines/brand/color-1
I've generally really liked the changes to bitbucket over the last few years in terms of UI and UX.
They also have an impressive component archive.
https://atlaskit.atlassian.com/packages
A lot of the packages are under an Apache 2 license, I can't say all as I haven't looked but the master repo is Apache 2.0 as well.