Open Rule Desiner

IBM announced the BlueMix pricing plan, the beginner you can have a one month free trial .The idea of BlueMix is that a developer can create an application very quickly and get it deployed without having to go through the usual rigmarole of enterprise app deployment which can take weeks or months.
       Today I will talk about the rule service,IBM have public the rule designer for free to use.The only thing you need to just  download the  an Eclipse Helios 3.6.2 version. Decompress the Eclipse IDE archive,the Add Repository dialog, enter the following repository details.
Name: Rules Service Rule Designer
Location: http://rd-851-installer.ng.bluemix.net/

When you launch the eclipse you should see the below UI.

You can choose one of  two ruleset mode.

What is the difference of Classic rule engine and Decision engine

Main improvements for the Rule Execution Server are coming from the next generation engine called  Decision Engine (DE) which is now available for distributed.
Thanks to its ability to natively compile ruleflows and decision tables, and to generate Java bytecode in the ruleset archive (DE Java bytecode), Decision Engine offers Major Enhancements, and impressive performance over previous releases :

DE is much more scalable than CRE
With HTDS REST and SOAP, the performance are more stable when the number of concurrent execution is raising.
With Decision Engine you :
Need less JVM tuning than CRE (no extra JIT configuration)
Can deploy the Rule Execution Server (RES) on machines/devices with limited resources, so enabling new use cases or application architecture.

If you are a rule newbie,you can reference the http://pic.dhe.ibm.com/infocenter/dmanager/v8r5/index.jsp to learn more abut usage.