Unzip the archive to, let's say, $HOME/games/, make sure you have all necessary dependencies installed, cd $HOME/games/netradiant_src/ and make. If you followed instructions outlined in the COMPILING file, you will get install/ folder inside of netradiant_src/
You can move install/ folder into $HOME/games/ and rename it into netradiant/ ; cd into the folder and launch NetRadiant as ./radiant
Steel Storm 2 © 2008-2011 Kot-in-Action Creative Artel; All rights reserved. Steel Storm, Steel Storm 2, Tomes of Mephistopheles and Kot-in-Action logos are trademarks of Kot-in-Action Creative Artel in the United States of America and elsewhere. All other trademarks are the property of their respective owners.