Compare two versions of a Rockwell project. Load both on the Home page first (they're kept side by side), then pick the older Version A and newer Version B below. You'll see what changed: hardware, I/O channels per tag, ladder/ST code, and tag initial values (from the last L5X save — same Decorated/L5K data the Ladder Viewer shows). Unity (.zef/.xef/.xbd) comparison is a later iteration — this build compares L5X.