Maybe you should read the FAQ again. All your questions have been answered already there.
Greenbone started to lead the development, added several software components and turned OpenVAS into a vulnerability management solution still keeping the values of free software.
after the release of the OpenVAS 9 framework it got renamed to Greenbone Vulnerability Management (GVM) and released as Greenbone Source Edition (GSE). Since GVM 10 the term OpenVAS is only used for the scanner component as it was at the beginning of the project
Especially Which release contains which component