Mattermost

Avantages

That we can host it ourselves, for one. We used to use the free tier of slack, but quickly discovered that the message limit was causing issues when we needed to recall conversations had in the past. It's been relatively hassle-free in getting it set up, and the whole team love it! One or two of us (myself included) were inspired to brush up on some of our coding skills when we discovered it didn't quite have the integrations that slack did, and as such have learned a lot about how Mattermost is put together, and how to create bots to get the information we need via webhooks. The Mattermost developers and community at large have been very helpful in answering questions when we've come up against issues, and I have even got a couple of my integrations featured on the integrations page of their website!

Inconvénients

Really, not a whole lot. Ideally I would like to be able to sign into multiple slack servers from the mobile app (though, the native app has really come along in leaps and bounds recently). The only thing I miss from the Slack days is a sidebar/widget that tells you the local times of the other users (handy when working with folk from overseas!), though we have recently developed our own slash command to return this information, it would be nice if it was built in to the server. I should probably feed this back to the devs.... ;)

Avantages

One executable binary, simple to upgrade and maintain!
Reliable self hosted alternative to other SaaS PaaS options.
Cross-platform applications ready to use.
Amazing open source community built around the product, friendly and helpful people!

Inconvénients

It requires integration directory to allow users app deployment in mattermost ecosystem with ease.
A bot repository is missing, this can fir next to all others apps and allow users automatic deployments of any apps from the store.
Store idea is not a new concept, and a company that respects themselves should make use of own repository.
Allow users to safely deploy tested and 100% working apps along their Mattermost instance.

Avantages

Open source and self hosted, I don't get irritated if slack goes down and I don't have to worry about my data security or my data just being lost of the company goes belly up. This is far and away our primary reason for using this instead of Slack,Hipchat,Cisco, etc.

It doesn't ask anywhere on this survey, but we use it for about 80 people, 60 staff and then various clients and contractors. We don't use many of the enterprise features, we just pay the licensing to support open source.

Inconvénients

iOS and Android Apps are pretty idiocy, they're getting a bit better, but they are easily the worst part and I field lots of complaints about them. I would trade all new features and other fixes for faster and more reliable apps. The web interface is much better, but a bit buggy, nothing serious but little lags and quirks persist longer than I would expect.

The install process is also a bit silly, copy pasting files and such, a provided .deb or a custom apt repository would be 100x better and save me upgrade time and downtime. The lack of this is surprising considering almost all other software I use has this, even when it is free or small.

Avantages

My company has over 200 employees ranging multiple departments (from editorial to strategy to support) and offices. Mattermost helps us stay connected in a quick and efficient way because we can easily connect and disconnect from channels according to our business or personal needs. For example, I am part of a group that connects members of my immediate editorial team and other groups that connect my larger team, my support resources, and strategy team members. It helps me stay organized in my communications, and it's much easier than using email or texting to communicate quickly with people on a daily basis.

Inconvénients

Because my company is relatively large, we have dozens of channels on Mattermost. I sometimes find it difficult to find specific channels that I'm not already a part of, especially if I don't know the precise name of the channel or group. This sometimes ends up being a hindrance to what is typically quick and efficient communication. Nevertheless, I enjoy using Mattermost and would recommend it to other businesses.

Avantages

* The replacement of slack
* Mattermost has almost the same features as Slack
* You can host and run your own instance on your own server (For companies which hate clouds) :)
* You have a good overview of logs and you can see what goes around
* The statistics gives a good point when a dev team is productive
* You can easily create unlimited integrations which some internal stuff

Inconvénients

* The lack of integrations (Slack is here over the top)
* The incoming hook limitation of maximum content length is the hell (Mattermost don't inform the customer about a message which was higher above the hard coded message size limit)
* UX in Slack is a little bit better (Slack is massively using websockets and eventstreams to fetch the actual team messages) -> You see always whats going on
* A 'Unread' channel (like in slack) would be a pleasure ;)
* A step by step guide for creating an integration would not bad for not advanced users