Open Source Journal

A journal is the one document you write assuming no one else will ever read it, which makes where the entries physically live the whole point - a private thought stored on someone else's server isn't private, and a diary you can't export is a diary you can lose. The open source options here keep your entries as plain files or encrypted text on your own machine, versioned or synced however you choose, so the most candid thing you write stays under a lock only you hold.