CastleDB

Provides a familiar spreadsheet editor with data validation, making it easy for users to input and manage structured data, as shown in the README screenshot and description.

Uses newline-formatted JSON to enable diffing and merging with Git or SVN, facilitating collaboration and local experimentation before committing changes, as highlighted in the collaboration section.

Changes are made locally, allowing for offline editing and controlled updates without relying on internet connectivity, unlike online spreadsheet editors that require constant access.

Allows columns to reference rows from other sheets, simplifying data relationships and validation, as described in the data model section for easing user input.