The Saito Scriptorium is a module used to develop scripts that add higher-level scripting features to Saito modules and NFTs. If you are new to Saito Scripting, you can get an introduction to the underlying concepts and learn how to write scripts on on dedicated scripting page.
The image above shows the script being developed on the left, the witness data needed to evaluate it, and a number of tools towards the bottom used when writing apps, like the ability to sign messages (with the privatekey of the browser) and generate hashes, etc.
The Scriptorium is used heavily by many of the more powerful Saito applications and features, such as the Saito Vault, which uses scripts to restrict access to privately stored and encrypted transaction data.