zfec is a fast, portable, and programmable implementation of erasure coding. It includes a C library, a Python library, and a command-line tool. Erasure coding is also known as "forward error correction", which is the generation of redundant blocks of information such that if some blocks are lost then the original data can be recovered from the remaining blocks. The RAID-5 algorithm is an erasure code, but while RAID-5 can recover from the loss of any one element, zfec can be parameterized to choose in advance the number of elements whose loss it can tolerate.
zrep provides an easy-to-use program to manage zfs filesystem replication and failover. No configuration files are required. The program is developed under Solaris, but may work with any up to date zfs implementation. The executable is a single script. Initialization does a full data copy, but subsequent syncs are incrementals. It uses internal locking to make sure there is no danger of overlap if you just shove it in cron to run every minute. Design target is more "near-time replication", since the sync can be run every minute or more. However, it could conceivably be used for "backup" purposes as well.