CyproTrader.org allows users to create, backtest, and then actually live trade using trading algorithms. Basic algorithms such as the 10/21 EMA are provided as examples, but using coffeescript can be customized exactly to users liking.
The trading bots themselves run on VPS’s, one per user, so scaleability should not be an issue. Currently works on both MtGox and BitStamp.
Dojima is a PyQt Bitcoin Exchange Client. Works with BitStamp, BTC-e, and CampBx.
Goxtool is a trading client for the MtGox Bitcon currency exchange. 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.Goxtool 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.
Goxtool can be used as a base for building a variety of different trading bots. Here are a few examples:
- (tailing) Stop Loss/Start Gain Strategy for goxtool – BitcoinTalk Thread
- Portfolio Rebalancing Strategy for goxtool – BitcoinTalk Thread
RTBTC is a trading platform that provides some more advanced charting than the exchanges do themselves. It currently supports MtGox and ties into your account via an API key, allowing trades to be placed directly via the RTBTC website without having to use MtGox’s web page at all. This is a subscription service. It’s by the clark moody, the guy who wrote the free charting application at bitcoin.clarkmoody.com.