CryptPad is an open-source collaborative office suite in which content is end-to-end encrypted. The suite includes rich-text documents, spreadsheets, presentations, forms, kanban boards, code and Markdown editors and diagrams, with real-time editing and a shared drive. CryptPad is a web application: you use a public instance, such as the flagship instance cryptpad.fr, or run your own instance, for example with Docker.
CryptPad is developed by XWiki SAS in Paris, France, and released under the AGPL-3.0 licence. According to the project documentation, the browser encrypts the data before it is sent to the server, so the server stores encrypted content. XWiki administers cryptpad.fr itself, but other instances exist that are run by third parties. Where your data is stored therefore depends on the instance you choose; with your own instance you control both the location and the administration. For a European organisation this means a French company as developer and a choice between a hosted service and full self-hosting.