Collaborative Writing and Communication

We have to decide how to write on the paper together. For various reasons I would like to choose another provider than google docs. One possibility is authorea (https://www.authorea.com). As Tennant et al. 2019 describe there are also other possibilities. However, I would like to use something that guarantees data security and is preferably FOSS. In addition, I don’t know anything about latex, which makes other programs more difficult for me. We also have to decide if it should be an open or a private document. I would prefer an open document, so that it is always possible to participate and to make additions or comments.
Do you agree to use authorea? Do you prefer another tool and if so which one? Should it be an open or a private document?
Flavio Azevedo: Yes.
Kwok Ng: Yes
Danny Haelewaters: Happy to try this.
Rohit Goswami: Would maybe prefer GitHub as then we could host a markdown file along with all the supplementary data. We could also keep discussions here as well. GitHub would also be easier for external contributors as they could open pull-requests. We could also use Gitlab but that has a smaller user-base (for public repositories).
Hendrik Tevaearai Stahel: Yes, I do. I am not very familiar yet as I just discovering it but it looks very convenient.
Lamia: I have no problem with authorea, but I think Rohit's suggestion is worth consideration as well.
Max: Authorea looks fine and more convenient for someone like me who never really worked with GitHub. Public document is fine, too.
Tarandeep:  I’m not familiar with the software, but it looks very easy to use, therefore I  support the idea. 
Helen: Yes and happy with open.
AlexA: yes. Happy to learn new tools.
Monica: Authorea is fine. Open is always ideal for me
Tobias: Happy to try Authorea!
Olmo: Yes, this looks useful. I'm no expert in GtiHub and Markdown, but would be willing to learn.
For communication, we can use e-mail. However, sometimes it is easier to have a chat/forum. I suggest mattermost because it is open source and logs the chat.
Do you agree to use mattermost? Please complete the table at the end of the document (E-Mail Address)
Flavio Azevedo: Yes.
Kwok: I've never used it before, but sure. 
Danny Haelewaters: I have used Slack before, which seems useful for project-specific communication and discussion.
Rohit Goswami: If we are open source I would suggest Zulip (they have no limitations for open-source and educational content) [https://zulipchat.com/for/open-source/]. As I understood mattermost is self-hosted right? Wouldn't that be an issue?
Lamia: Never used it either. I'm down with whatever you choose.
Max: Yes.
Tarandeep: yes
Helen: Not used it but happy to try. 
AA: I've never used it, but I can learn
Olmo: Same
Twitter: I would also like to be able to send you messages on twitter, therefore it'd be great if you'd all follow me. Thanks a lot!