An open source Slack clone written in Golang and React

j_s wrote: post #7

chedabob wrote: post #3

Now part of Gitlab: https://about.gitlab.com/2015/08/18/gitlab-loves-mattermost/

Interesting licensing (normally AGPL/commercial but MIT just for Gitlab); I'm interested to find out more about how this is even possible: 1) "GitLab Mattermost" is available under an MIT license as a compiled version of "Mattermost", and 2) the MIT license does not apply to the "Mattermost" source code https://gitlab.com/gitlab-org/omnibus-gitlab/issues/654

I guess they are saying all of the Gitlab code is MIT and all of the Mattermost code is AGPL. That's perfectly permissable by both MIT and AGPL licenses.

In practical terms, you can take the Gitlab/Mattermost distribution and modify the Gitlab code without having to release your changes. But if you modify the Mattermost code, you need to release the changes you made to the Mattermost code.

Re: An open source Slack clone written in Golang and React

#9

Post by icebraining » Tue, Sep 22, 2015, 2:56 PM UTC

RyanZAG wrote: post #8

j_s wrote: post #7

Earlier quoted context omitted.

Interesting licensing (normally AGPL/commercial but MIT just for Gitlab); I'm interested to find out more about how this is even possible: 1) "GitLab Mattermost" is available under an MIT license as a compiled version of "Mattermost", and 2) the MIT license does not apply to the "Mattermost" source code https://gitlab.com/gitlab-org/omnibus-gitlab/issues/654

I guess they are saying all of the Gitlab code is MIT and all of the Mattermost code is AGPL. That's perfectly permissable by both MIT and AGPL licenses. In practical terms, you can take the Gitlab/Mattermost distribution and modify the Gitlab code without having to release your changes. But if you modify the Mattermost code, you need to release the changes you made to the Mattermost code.

No, if Mattermost and Gitlab were linked, the AGPL restrictions would apply to the Gitlab code, even if it's MIT licensed. Otherwise, anyone would just be able to make a MIT-licensed wrapper around an AGPL project, allowing indirect linking between proprietary code and AGPL.

What Mattermost apparently did was compile their own code (under the name "Gitlab Mattermost"), and distribute that compiled version under MIT, so there's no AGPL in the Gitlab distribution.

Re: An open source Slack clone written in Golang and React

#10

Post by icebraining » Tue, Sep 22, 2015, 3:02 PM UTC

j_s wrote: post #7

chedabob wrote: post #3

Now part of Gitlab: https://about.gitlab.com/2015/08/18/gitlab-loves-mattermost/

Interesting licensing (normally AGPL/commercial but MIT just for Gitlab); I'm interested to find out more about how this is even possible: 1) "GitLab Mattermost" is available under an MIT license as a compiled version of "Mattermost", and 2) the MIT license does not apply to the "Mattermost" source code https://gitlab.com/gitlab-org/omnibus-gitlab/issues/654

From what I can tell, the dev team of Mattermost is essentially releasing two versions: you can get the original source under the AGPL, or a compiled version under MIT (called Gitlab Mattermost). Since they own the copyright, they don't need to abide by the AGPL when producing the compiled version.

An interesting side effect is that if you were able to decompile that version, you could in theory have a MIT license to the Mattermost source, avoiding the AGPL.