I tested the 'ssss' package in Linux, an implementation of Shamir's secret sharing algorithm. link
The package is easy to use, and I presume that it is cryptographically valid implementation, though I have not personally verified that. How standardised is this implementation? It appears that the package is quite old, which is probably a good sign. But I am wondering whether a version of Linux (or other OS) in ten or twenty years' time is likely to be able to recover the secret from the shares, or is it advisable to retain a copy of this specific implementation? For example/comparison, I am very confident that some md5 algorithm will still be available for a long time on any pc, and produce identical results to a current implementation.