Crashplan did it all...
Crashplan had a pretty unique product, and could probably have made more money out of it if they wanted to.
Crashplan gave me:
* Windows, Linux, Apple clients.
* Backup peer-to-peer (excellent for family members, laptop, backing up to my desktop).
* Backup to cloud (belt and braces copy).
* Backup to local disk (quick-to-restore copy).
* Versioned file changes.
* Long-term retention of deleted files.
* Reasonable pricing for multiple machines (e.g. family group).
* Unlimited or very cheap storage.
The well-known ones like Backblaze, SpiderOak, Carbonite all tend to be OK for a single computer, but get very expensive backing up multiple machines (e.g. for a family).
* Duplicati, perhaps?
* Arq looks like a possible alternative, but doesn't work on Linux
* Goodsync, perhaps, but it doesn't keep history.