RelEx is a relation extractor software (https://github.com/opencog/relex).
In order to make it easier to use it from perl(or any other language) for a few questions at a time I made this simple Http server to query RelEx quickly.
Open the project in eclipse then add all the needed library for relex as external jar then relex itself as external class path (see http://wiki.opencog.org/w/RelEx_Install for the list of library), you also need to put the data file in the project folder. Then you can compile and start the program
You can download a tgz containing the .jar here http://download.rom1504.fr/RelExHttp/RelExHttp.tgz, but you still need to install wordnet and link-parser (see http://wiki.opencog.org/w/RelEx_Install) to run it.
First start the program, then you can query RelEx with : curl http://localhost:9002/ --data-urlencode "text=Who is the daughter of Bill Clinton married to?"