Quite amusingly, the project is called Librelist. The official website introduces it quite well, so I'll just quote it:
Librelist is a free as in freedom mailing list site for open source projects. It is a place for FOSS communities to discuss all the things they want without ads, censorship, signup requirements, bundled apps, or requirements that you use any particular email client or service.
Anyone Can Make A List
You can make a mailing list by simply sending an email to firstname.lastname@example.org, and if it doesn’t exist, it will make it for you and subscribe you. That’s all there is to it, and no restrictions on making the lists.
Anyone Can Subscribe To A List
You also subscribe to a list by simply sending your first message to email@example.com. That’s it. It ditches your original message and sends you a confirmation you reply to. No signup or web forms involved.
Spam And Bounce Blocking
Spam is heavily blocked on all lists to keep things clean. We will also periodically ban anonymous email services if they become a vector for abuse.
Bounced emails are caught and anyone who bounces has all of their subscriptions paused until they can fix the problem and reinstate themselves.
############ End quote
I would like to add that Librelist is a much need alternative to existing mailing list solutions. Let's say that a group of people are trying to collaborate over a FOSS project. These people usually need a mailing list. What options do they have?
There are two sets of options: (1) commercial solutions and (2) self-hosted open-source solution.
Commercial mailing list providers, such as Google and Yahoo, have a lot of resources in their disposal that could in principle be used for providing a great mailing list service. But that's not what happens in practice. To paraphrase a comment from Librelist's founder Zed Shaw, Google and Yahoo optimize their services to give the best experience for the user; Problem is, from their perspective, the "user" is not the person trying to communicate on the mailing list, but the advertiser paying Google/Yahoo for advertising on the mailing list.
Needless to say, this does not result in a very good experience for the actual user. I know personally some people who manage a mailing list hosted by Google, and I was told there are many problems with it, specifically an abundance of spam and lack of good tools for dealing with it.
The second approach is to use mailing list software such as mailman or piper. This has two problems:
(1) It requires a server for hosting the list, and a system administrator to configure and maintain the mailing list. For some projects this is a big barrier, for others it's merely a waste of time and resources.
(2) The popular mailing list programs are not very good. Take mailman for example, which is used for this mailing list. It does many things which may have been considered acceptable 10 years ago, but not today. The subscription process is cumbersome, the program sends the user his password in plain text, and generally its interface looks like a 1995 website.
So there aren't very good options for a group that needs a mailing list. I would like to note that I have been in this exact situation recently, as I needed to make mailing lists for my open source projects. I just couldn't find a good solution. This is how I found Librelist.
And I would say, that the biggest disadvantage Librelist currently has is this: Since it is a relatively new community project, it's hard to trust that it will stay operating and well-maintained for years. People don't want to start a mailing list on a service that might get closed 6 months from now. The founder of Librelist seems enthusiastic enough, but this is a non-profit project for him, so it's impossible to be certain that he will not become too busy for the project in the future.
I think that the FSF should sponsor this project. I think it wouldn't require a big amount of resources, but it will require the persistence and reliability over time that FSF can provide.
This will solve the concern I mentioned above, and will make Librelist a very attractive choice for people who want to collaborate.
I'd be happy to hear any comments.