cattaDoc has been tested on Apache as well as Microsoft Internet Information Server (IIS).
Apache is open source and is included in most Linux distributions or can easily be installed using a Linux package manager, e.g. YAST in OpenSUSE or Synaptic Package Manager in Ubuntu.
The open source Apache web server can be downloaded from httpd.apache.org, e.g. for Windows.
Microsoft includes a web server with Windows, i.e. it is free for all Windows users, but not installed by default on desktop or workstation editions of Windows.
Here is what you do to install it - make sure you have the Windows installation CD:
After installation of Internet Information Services you might have to reapply the latest Windows service pack in order to ensure that you have the latest patches and security fixes for IIS.