Novel Insight Inner Circle is a message and file encryption tool for Windows. The software is developed in Java and requires 64bit Java JRE. The encryption uses AES-256 twice so it is harder to crack than the industry standard pure AES 256bit implementation (theoretical key size is 512 bit). The software writes encrypted data in ASCII text format which can be cut'n'pasted to messaging apps or to emails and back to Inner Circle when decrypting data.
IpChat is a comprehensive network communication tool, similar to a regular instant messenger. However IpChat unlike other IM networks is completelly decentralized, requiring no pre-existing server.
Island is a Serverless LAN Based Instant Messaging Tool that reaches anyone in the same subnet by using TCP/IP broadcast notifications. There is no need to add contacts since all of them are there.
This web service developped in Java provides WebForum services on the IMAP4/POP3 protocol : you don't need database, and common messaging tool like Netscape Messenger or Outlook permits to create/delete new forum and to moderate messages.