The following is a list of instant messaging protocols .

Initiative

• .NET Messenger Service
• OSCAR (AIM and ICQ)
• TOC protocol (AIM)
• YMSG(Yahoo! Messenger)

Third-party

• Gadu-Gadu
• Gale
• Internet Relay Chat
• Jabber
• Lotus Sametime
• PSYC
• Session Initiation Protocol
• SIMPLE
• Voice over IP
• Zephyr Notification Service