Off-the-Record Messaging (OTR) is a cryptographic protocol that provides encryption for instant messaging conversations. Developed by Ian Goldberg and the OTR Development Team
License: Open Source
Telegram is a versatile messaging app with a focus on group chats and cloud storage, while Off-the-Record Messaging emphasizes privacy and security with default encryption and no metadata storage. The choice between them depends largely on the user's needs for functionality versus privacy.