Android is one such system. Each app gets its own image (called Bundle) where it can store it's state. OS manages those state bundles to offer multitasking on memory-constrained devices and persist app state across reboots.
Android has a file system. It's a operating system (a Linux variant). I'm suggesting that neither a file system nor an operating system is necessary, or even desirable. Just run an interactive programming language continuously on the bare metal, with its image periodically backed up to secondary storage.
