Bfxtool is a trading client for the Bitfinex.com trading platform. It is designed to work in the Linux console (it has a curses user interface). It can display live streaming market data and you can buy and sell with keyboard commands.
Bfxtool also has a simple interface to plug in your own automated trading strategies, your own code can be (re)loded at runtime, it will receive events from the API and can act upon them.
The bfxtool is developed from another trading client goxtool https://github.com/prof7bit/goxtool which is not in demand now, but was used as skeleton for the current project.
The user manual for bfxtool is the same like for goxtool and could be read here: http://prof7bit.github.com/goxtool/