Fractum is a portable secure file encryption tool allowing you to encrypt files and split them into multiple shares, with the ability to decrypt using only a subset of these shares.
Shattr is a website where you can split your secrets into several shards such that if a certain number of them are combined, the secret can be recovered, but otherwise, no information about the secret can be obtained.
ssss is an implementation of Shamir's secret sharing scheme for UNIX/linux machines. It is free software, the code is licensed under the GNU GPL v2. ssss does both: the generation of shares for a known secret and the reconstruction of a secret using user provided shares.