Install PHPlib (http://sourceforge.net/projects/phplib) if it's not already installed. Note that with recent versions of PHP, PHPlib needs to be patched. Please do the following with the patch file, page.inc.patch in the distribution directory:

cat page.inc.patch | patch -p0 -b /path/to/phplib/page.inc

Make sure you replace /path/to/phplib with the actual path to the installation of PHPlib. On windows systems you can edit page.inc and change line 67 from if (isset($user)) { to if (isset($user) && $user) {.

Optional: Install JpGraph (http://www.aditus.nu/jpgraph) if you wish to use it for the summary bug display on the home page.

Copy the directory tree from the tarball (or zip archive) to a location suitable for serving web pages.

With your web browser, go the location where you installed the package. You will be presented with a web page that will help you configure and install the application.

After completing the installation, login and start reporting bugs.