COI - Chat Over IMAP - is a universal chat protocol that is Free, Open, Easy, Safe and does not require developers to build or maintain a server. COI uses an email address and any IMAP server as its infrastructure. This means it can already connect 3.8 billion users - anyone with an email address. Developers can now concentrate on building clients for any device, in any language (Java, Swift, JavaScript, Dart, Kotlin, etc.), and let COI handle the communication.