A list of random forest implementations, most of them open source / free. Apart from Salford Systems and Statistica most of the large commercial data mining packages have been slow to adopt, although SAS has recently introduced a random forest capability.
Open Source / Free
FastRandomForest for Weka
Orange – part of a data mining suite of tools.
R randomForest package
RapidMiner random forest and Weka Random Forest
scikit-learn – Python based implementation of random forest
Weka random forest also available in Pentaho Community Edition
bigML – particularly easy to use implementation from new startup.
Salford-Systems – some might argue the best random forest implementation available.
wise.io – very fast random forest implementation