Futurecloud.io

A deployment of NextCloud which has many amazing features such as video/voice/chat conferencing, military-grade encryption on cloud storage and a lot more. Can be deployed on many different server operating systems and for up to thousands of users. Software is free and open source but deployment may come with some costs.

The servers maintainence costs are minimal and are primarily related to hosting and the occasional upgrade and updates. Cost can be further reduces by self hosting the instance locally as opposed to on the cloud.