You can use a .htaccess file (or better apache.conf) to forward all requests to index.php with mod_rewrite:
Options +FollowSymLinks
IndexIgnore */*
<ifmodule mod_rewrite.c>
RewriteEngine on
# if a directory or a file exists, use it directly
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# otherwise forward it to index.php
RewriteRule . index.php
</ifmodule>
If your request is http://www.example.com/controller/view, than $_SERVER['REQUEST_URI'] is /controller/view. You can interpret it with Regex or by simply splitting string: explode('/',$_SERVER['REQUEST_URI']);