I was wondering how many online brokers/trading firms and Real time quote providers offer an API so users can write their own software to hook on their servers. Is IB the only broker offering this service?
Cybertrader has a full API for both data and brokerage. Support availabel for C++, VB and Delphi. Check out the support group on Yahoo at http://groups.yahoo.com/group/CyBerAPI_Development Echo
I would not advise bothering with the Patssystem API. It's not an API for J-Trader to just put in orders but instead an API to replace J-Trader. Can you say a lot of work? plus all kinds of validation required because you have to go direct to their servers.