Open source

Open source refers to a software licence where source code access is regulated by set of published principles. There are many such licenses.

Free software is open source with added restrictions on the copyright, that cannot be revoked without violating the license under which you originally acquired the code.

Consortium licenses may be open source or not or mixed so that members have access to sources and others do not.

A Green software license probably would not qualify, as it would restrict unpaid use to Green purposes and might forbid some uses entirely.

Shared source is not open source, as it is controlled tightly by one vendor, e.g. Microsoft.