btrfs
btrbk is a backup tool for btrfs subvolumes, taking advantage of btrfs specific capabilities to create atomic snapshots and transfer them incrementally to your backup locations.
Related contents:
Btrfs Assistant is a GUI management tool to make managing a Btrfs filesystem easier.
Best-Effort Extent-Same, a btrfs dedupe agent.
bees is a block-oriented userspace deduplication agent designed for large btrfs filesystems. It is an offline dedupe combined with an incremental data scan capability to minimize time data spends on disk from write to dedupe.
an open-source btrfs driver for Windows.
WinBtrfs is a Windows driver for the next-generation Linux filesystem Btrfs. A reimplementation from scratch, it contains no code from the Linux kernel, and should work on any version from Windows XP onwards. It is also included as part of the free operating system ReactOS.