The easiest way to use the Rules Framework is to download a binary release, but if you want to access the latest development version, you need to get the Rules Framework sources and build them using the Maven 2 build environment.
The first step in building the Rules Framework is to check out the Rules Framework sources from the Subversion source repository at http://rules.svn.sourceforge.net/svnroot/rules/. The source tree is divided in the standard parts: trunk, branches, and tags. The latest development version is found within trunk, while the other parts are used to keep track of the source code of the Rules Framework releases.
The trunk contains the top-level build environment and a number of component projects within subdirectories. See the README.txt files within each subdirectory for a brief description of the component project.
You need a Subversion client to access the Rules Framework source repository. Take a look at the Subversion client list unless you already have a client installed. Once you have the Subversion client installed you can checkout the main Rules Framework source tree with the following command or its equivalent in the client you are using:
$ svn checkout https://rules.svn.sourceforge.net/svnroot/rules/trunk rules
The above checkout will create a subdirectory named rules that contains the latest Rules Framework sources. See the Subversion book or the documentation of your Subversion client for more information on how to manage your source tree and keep it up to date with latest development.
The Rules Framework uses Maven 2 as the build system and the component sources are organized according to the Maven Standard Directory Layout. The standard build environment is Maven 2 with the Java Development Kit (JDK) 1.5.
See the Running Maven page and the related documentation on the Maven web site for instructions on how to use Maven. You may also want to check for Maven 2 integration with your favourite Integrated Development Environment (IDE).
There are Maven project descriptors (POMs) within both the top level Rules Framework directory you checked out above and all component subdirectories. The easiest way to build the Rules Framework is to use the "multimodule" setup within the top level directory:
$ cd /path/to/rules; mvn -Dnet.sourceforge.rules.provider=drools install
This will build and package all the component projects and place the resulting artifacts within your local Maven 2 repository. You can also find the artifacts within the created target subdirectories of the component projects.