Earlier quoted context omitted.
What about the Android SDK? I don't think that this is open source, is it? As a developer, when you download an Android SDK you have accept a licence that is not open source, right?
Yeah. It is [1]. Surprisingly, Android Studio is open source too [2]. [1]: https://android.googlesource.com/platform/sdk/+/refs/heads/m... [2]: https://android.googlesource.com/platform/tools/base/+/studi...
And I didn't expect Android-Studio to be open source!
[1]: https://android.googlesource.com/platform/sdk/+/refs/heads/m...