We are interested in Splunk but we need to know which open source package are shipped within Splunk and which version
I think this is what you are looking for.
http://docs.splunk.com/Documentation/Splunk/4.3.2/ReleaseNotes/Credits
I think this is what you are looking for.
http://docs.splunk.com/Documentation/Splunk/4.3.2/ReleaseNotes/Credits