Name: Blackbird
Program: C++
Download: https://github.com/butor/blackbird
Exchange: Bitfinex, OKCoin, Bitstamp, Kraken, ItBit, Gemini
Name: Gekko
Program: Javascript / nodejs
Download: https://github.com/askmike/gekko
Exchange: Bitstamp, CEX.io, Kraken, BTC-e, Bitfinex, LakeBTC, Cryptsy
Name: Bitcoin Arbitrage
Program: Python
Download: https://github.com/maxme/bitcoin-arbitrage
Exchange: Bitstamp
Name: Bitcoin Dealer
Program: Django
Download: https://github.com/rokj/bitcoin_dealer
Exchange: Bitstamp
Name: BTC-E Arbitrage Bot
Program: PHP
Download: https://bitcointalk.org/index.php?topic=236321.0
Exchange: BTC-e
Name: Crypto Arbitrage Trader
Program: Python
Download: https://github.com/PeanutPower/CryptoArbitrageTrader
Exchange: Coins-E, BTC-e, Vircurex, Cryptsy
Name: tAPIbot
Program: Python
Download: https://github.com/nomorecoin/tAPIbot
Exchange: BTC-e