Comment by ksec

Open Source as defined by OSI, which means BSL is not considered as Open Source.

Open Source as defined by majority of programmers on Internet, which means either GPL, MIT, or Apache and their derivatives.

Open Source as defined by HN, depending on which timeline you join HN, it could be MIT, BSD only all the way to AGPL only.

Open Source as defined by layman, anything I can see its source is considered as Open. Open Source in its literal sense.