AGPL License

Hi there. Very impressed with SiYuan. High quality project 🎉

I am exploring building an app to support language learning. As the basis of the app I'd like to use SiYuan. The users would "collect" their language material and this would form the basis of their current knowledge with respect to known words, topics etc.

Obviously this would require quite some extending to understand content down to the word (or lower) level. This would involve backend as well as frontend changes. The app would also have a commercial tier too.

I understand the restrictions of GPL and AGPL to some extent. But i'm asking this question to get a bit more info from the project maintainers. Can you confirm/expand on the following please:

• the amended source code would need to be made available. Would this be both front and backend?
• is it possible to make a closed source plugin and allow users to upgrade to install it? If so, how would that work as it'd be outside the bazaar?
• are there any other examples of projects built upon SiYuan?
• anything else you'd like to expand on?

Thanks in advance!