Letter is a place to read and engage in thoughtful conversation. A conversation is a public exchange of written letters. Conversations are public to read, follow, and share, and anyone can sign-up and start a conversation. However, once a conversation is started only the writer and recipient of the initiatory letter can participate in that conversation. If Twitter is the town square where conversations start, Letter is the cafe where thoughtful conversation has time and space to flourish. https://letter.wiki/about