A C compiler (ANSI or non-ANSI) if you are installing it on Unix.

You should be familiar with Unix operating system in order to install it on Unix. I think if you know what ls command is, you qualify. If your site is configured to run CGI programs from users' space, then you will not need root access otherwise root access is needed.

If you are installing on NT, a self extracting binary is available. Setup Wizard will guide you through the installation.

You must run a web server. The web server must be capable of running standard CGI programs. If you run several web servers in your domain, you can install the counter in one server and allow the users at other servers to access the counter remotely.

The web server must be running on any of the Unix, NT, OS/2, VMS or Amiga Operating System.