Nextcloud - Online collaboration platform
Sourrce-code: https://github.com/nextcloud/server
Tarsnap - Online backups
Tarsnap is a secure online backup system for UNIX
Filen – Next Generation End-To-End Encrypted Cloud Storage
Next Generation end-to-end encrypted cloud storage. Get started with 10 GB of free space.
Dropbox
Dropbox is a modern workspace designed to reduce busywork-so you can focus on the things that matter. Sign in and put your creative energy to work.
MEGA
MEGA provides free cloud storage with convenient and powerful always-on privacy. Claim your free 20GB now