Principles of open source
Are all the modules open to download the source code?
Different modules have different opening strategies.
Application layer cab be open source for all public. Any third-party could download it directly.
API interfaces of cloud security is open. It can be used by the client.
Layers of the core are against viruses and Trojans. So it is not fully open to the public, but the third party can apply to become a core developer after the inspection.