Redlog is integrated with the interactive computer algebra system REDUCE. REDUCE is available on SourceForge with project name "reduce-algebra". Your can download binary distributions for Microsoft Windows, Apple MacOS, and several versions of GNU/Linux.
Simply click the green button at the top to download the latest build. SourceForge uses heuristics to pick the most appropriate distribution file for your platform automatically.
Note that there is no automatic update facility; to update REDUCE just install it again. We recommend to do so regularly to keep track with the ongoing development of Redlog.
More Information can be found in the Obtaining REDUCE Section on the REDUCE Website.
The REDUCE source code can be obtained via SVN. A suitable link is available on the REDUCE Project page.
Compilation requires a "configure" and a "make" step, which works painlessly especially on unix systems (including MacOS) but might require the installation of some required packages. Once this is set up, you can easily SVN update and re-make
For more information see the Obtaining REDUCE Section on the REDUCE Website and the references there.