GridCraft
Open-source, clean-room spreadsheet (Microsoft Excel-style) in Rust
...The application also provides a command-line interface, JSON control channel, and Model Context Protocol (MCP) server that allow AI agents to create, modify, analyze, and automate spreadsheets. Available for Windows, macOS, Linux, FreeBSD, and web browsers, GridCraft operates without subscriptions or telemetry and is currently in alpha development.