Requirements
Java 1.5.x or newer, preferably from Sun. Set JAVA_HOME to the root of your Java installation.
Ant build tool:
http://ant.apache.org/. To run unit tests, you also need JUnit:
http://junit.sourceforge.net/.
Building Pig
Check out pig code from svn: svn co http://svn.apache.org/repos/asf/incubator/pig/trunk.
Build the code from the top directory: ant. If the build is successful, you should see pig.jar created in that directory.
To validate your pig.jar run unit test: ant test