icq messaging

LAN instant messaging.

Group chat and instant messaging for teams and small businesses.

Instant messaging server.

Popular instant messaging client supports a plethora of services.

Encrypted BBS style client for chat, messaging, and transfers.

Internal messaging system.

Highly Secure Email, Chat, Instant Messaging, and Collaboration.

Native OS X desktop client for the Yammer messaging service.

Instantbird is a multi-protocol Instant Messaging client.

Enterprise messaging/collaboration software.