1)   Akeni Enterprise Instant Messaging LDAP 2.2
Akeni Enterprise Instant Messaging IM is an enterprise messaging system that offers strong encryption, along with Active Directory / LDAP integration. Features includes IM chat, conference, file transfer, notification, alerts, optional web client.

 2)   BigAnt Instant Messenger 2.22
BigAnt Instant Messenger is an office instant messenger with business features, BigAnt Instant Messenger raises the level of collaboration and community for relatively low cost, only $1.9 per user this week. Check it out now!