Rockliffe
AstraChat - Direct XMPP Client
FreeAstraChat is a lightweight standalone Jabber (XMPP) client application that connects directly to your XMPP server without any proxies...
AndroidStealthChat: Private Messaging
FreeStealthChat is a secure app for calling and chatting with your friends and partners.
AndroidMailSite Collaborator SE
Trial versionBlock viruses and spam messages from accessing your server.
Windows