For a first time installation, go to the directory where you want to install Abyss Web Server. From now on, <Abyss Web Server directory> will refer to this directory.
Execute:
tar xzfm <Abyss Web Server installation package>
If you are upgrading, go to the directory where the old version of Abyss Web Server is already installed and execute the following commands:
mv htdocs/index.html htdocs/index.html.bak
cd ..
tar xzfm <Abyss Web Server installation package>
cd abyssws
mv htdocs/index.html.bak htdocs/index.html
If errors are reported when executing the first and the last command, ignore them: they occurred because you have no index.html file in the htdocs directory.