See the wiki homepage: https://github.com/evanx/vellum/wiki
At some stage, commmon utilities were copied to github.com/evanx/vellumcore, as a dependency for other projects.
Also dualcontrol code was copied to github.com/evanx/dualcontrol. However it is possible that more recent changes to that code were made here, for the purposes of the Dual Control article.
On that subject, also see github.com/evanx/keyserver - a Node.js re-implementation of the Java dualcontrol package. It provides a secure "vault" server with client-authenticated HTTPS access. It uses Redis to store encrypted data, and the encryption keys. Encryption keys are protected by split-knowledge passwords, hashed with PDKDF2, and encrypted using AES.