Platforms / macOS /
File Storage & Sync
Prefer
Borg
Compressing, deduplicating backup tool.
EteSync
Encrypted calendar, contacts and tasks sync.
Web Service
git-annex
Git-driven file management and version control.
Sia
Decentralized cloud storage.
Experimental
Syncthing
Direct file sync between devices.
Notes

This section has been carefully curated to only include software that encrypts data on the client. That means your data should be secure even if servers it’s stored on are compromised.

Avoid
Dropbox
Google Drive
iCloud
Microsoft OneDrive
Yandex.Disk
macOS Anonymizing NetworksBookmark SyncCollaborationDNSEmailEmail AddonsEnterprise SuiteFile Sharing
File Storage & Sync
FinanceInstant MessagingMedia PublishingMesh NetworksNewsOperating SystemsOperating Systems (Live)Password ManagersProductivitySocial NetworksVideo & VoiceVPNWeb Browser AddonsWeb BrowsersWeb SearchWorld Maps