I have a Apache server running at Rackspace Cloud Hosting, so I've installed Wordpress manually(setting up the database, wget the latest.zip...) and placed it at /var/www, but now when I try to access it for the first time, it downloads a strange file with the IP as name instead of showing me the Wordpress Installation.
PS: The same happens if I place it on a sub-directory like blog
I think you haven't configured Apache to execute PHP (mod_php?) Right now it's just serving your PHP files like any old file type so what you're getting is your wordpress index.php as a file download.
I'm not sure what the process is for Rackspace, but usually this would mean enabling mod_php.
Do you have any other PHP files that work on that site?
you need to tell Apache to excuate php files. add the following to your Apache configuration file:
AddType application/x-httpd-php .php
AddType application/x-httpd-php-source .php
make sure PHP module is included in Apache configuration first!
