climm

climm (previously mICQ) is a free CLI-based instant messaging client that runs on a wide variety of platforms, including AmigaOS, BeOS, Windows (using either Cygwin or MinGW), OS X, NetBSD/OpenBSD/FreeBSD, Linux, Solaris, HP-UX, and AIX. Functionality climm has many of the features the official ICQ client has, and more: It has support for SSL-encrypted direct connection compatible with licq and SIM. It supports OTR encrypted messages. It is internationalized; German, English, and other translations are available, and it supports sending and receiving acknowledged and non-acknowledged Unicode-encoded messages (it even understands UTF-8 messages for message types the ICQ protocol does not use them for). It is capable of running several UINs at the same time and is very configurable (e.g. different colors for incoming messages from different contacts or for different accounts). Due to its command-line interface, it has good usability for blind users through text-to-speech interfaces or Braille devices.