Downloading and running a prebuilt binary is certainly the easiest way to get started with Rej. Download the latest version, then extract the zip file that you have downloaded. Then, from a command line, change into the directory that was created and run java -jar rej.jar.
Rej depends on Jena, so you need to download and extract a recent release of Jena. See the Jena downloads page to obtain an archive of a recent release. After you have downloaded Jena, you will need to extract it. This is how you might do this from a GNU command line (such as with Linux, and assuming you are using version 2.5.7 of Jena):
$ unzip Jena-2.5.7.zip
You can get the Rej source from Subversion, for example by using the Subversion command line:
$ svn co http://code.infinitesque.net/legere/trunk/source/rej rej
You will also need to have Java (at least version 1.5) and Apache Ant installed. Installing Java and Ant is beyond the scope of this guide, however. Once you have these components, you need to change into the Rej source directory and execute the following command:
$ cd rej $ ant -Djenalibdir=/path/to/Jena/lib/ dist-standalone
This will compile Rej into an archive named dist/lib-standalone/rej.jar. The following command will run Rej:
$ java -jar dist/lib-standalone/rej.jar