Last week I was onsite with a new customer of ours, implementing **[Deltanji](http://georgejames.com/deltanji)** to give them control of their development and deployment cycle. One particularly satisfying part of the visit was seeing their pleasure at how their production class now records its changes over time, allowing them to quickly diff the versions and see what configuration items have been added or what settings altered. ​ With a few clicks in the Deltanji web UI they're also able to diff their dev environment's copy of the production class with their QA one and migrate appropriate changes between environments using the powerful [Beyond Compare](http://scootersoftware.com) diff tool Deltanji leverages. I raised the topic of versioning the production class in [this previous post](https://community.intersystems.com/post/source-control-and-production-class), and I'll be happy to give more information here in response to questions or comments.