Lionel Péramo

As it says, "The self-hosted alternative to Dropbox". If you have a server with sufficient resources, you can use this great self-hosted solution that handle a lot of things via plugins. It handles...

A great, free, open source tool as it evolves rather quickly and provides numerous features. If you know Slack, Discord etc. you should not be deceived by RocketChat.

There's room for improvement as it does not solve complex problems yet, but it's already a time-saving tool for numerous various tasks from ghostwriting, engineering and so on!