FISHR2 is the newest version of the FISHR (Find IBD Shared Haplotypes Rapidly) program and supplants the old version, FISHR, which was described in this publication. FISHR2 detects IBD segments between individuals from genomewide SNP data. It is implemented in C++ and designed to work on a UNIX/LINUX environment. It is maintained on github here: github.com/matthew-c-keller/FISHR2.
I highly recommend that you read the documentation and work through the provided R complete example posted on the github link above.