This document discusses versioning for workflow evolution. It presents a framework for managing changes to workflows over time that allows tracking how research encoded in workflows evolves. The framework captures workflow versions at different granularities and stores them using different strategies like delta encoding and checkpointing. An evaluation compares the performance of these strategies, finding that delta encoding with checkpointing generally performs best by optimizing storage usage, version access times, and recovery times. The framework aims to enable understanding and managing the knowledge embodied in evolving workflow executions.