SecuXabber is a secure Jabber-client for Android that uses strong, asymmetric encryption on top of the XMPP protocol. A key pair is generated on application start-up. Users can send their public key to other SecuXabber users via Bluetooth. This face-to-face check ensures the veracity of the public key. After the keys have been imported by both users, all communication between them is encrypted using strong 4096 bit encryption. It supports all relevant XMPP features, works with multiple accounts, is highly customizable, and has many other useful features.
Scopserv Communicator is an audio/video Internet phone and instant messenger that supports some of the most popular VoIP and instant messaging protocols such as SIP, Jabber (XMPP), AIM/ICQ, MSN, Yahoo! Messenger, and a whole lot of other useful features. ScopServ Communicator is based on the SIP Communicator softphone.
jabberd is a Jabber/XMPP instant messaging server. It implements XMPP-Core (RFC3920), XMPP-IM (RFC3921), and a range of protocol extensions: XEP-0012, XEP-0016, XEP-0030, XEP-0049, XEP-0054, XEP-0077, XEP-0079, XEP-0092, XEP-0114, XEP-0138, XEP-0153, XEP-0157, XEP-0160, XEP-0191, XEP-0192, XEP-0193, XEP-0198, XEP-0199, XEP-0202, XEP-0203.