> So I'm pitching this to bored devs and entrepreneurs: Help us, and many other projects, by creating a "Github for mailing lists"

Hi. I'm from the Discourse team, and I recently "soft-pitched" an idea that seems very much in line with what you're looking for.

https://meta.discourse.org/t/becoming-the-new-standard-discu...

Regardless of the above, we're gonna be doing a significant push for better mailing list features during the months to come, so any feedback you or any other open source projects may have, please nudge me on meta.discourse.org or send me an e-mail (my first name, erlend, at the company domain).