macOS Sync
Coming soon, in development.
macOS Sync runs on your Mac and keeps a local folder in sync with your InterlinedList documents as Markdown. Changes you make locally are pushed up, changes made on InterlinedList are pulled down, and conflicts are never silently overwritten, so you can use your own editors while everything stays connected to your account.
Until it ships, any tool can sync documents with a personal access token; see Document sync & the CLI.