requirements:
-rtorrent 0.7.8, compiled with "--with-xmlrpc-c"
 -xmlrpc >= 1.07
-some webserver
-php5, with the following extensions:
 -xsl (libxslt1.1)
 -xmlrpc

installation:

you might need the following packages: make, libcurl-openssl-dev, pkg-config, sigc++-2.0-dev, libncurses-dev

to install xmlrpc, get the source from here: http://sourceforge.net/project/showfiles.php?group_id=16847
in my case, i could only compile the 1.11.00 version (due to a known bug, you may try to configure with --disable-cplusplus, if the compiling stops with some syntax error)
of course, you can try any version, over 1.07 (or any version over 1.00, but you'll get incorrect data for values bigger than 2^31-1, since it does not support 64bit integers)
follow the next steps, as root (this step is not needed, if you're upgrading from a pervious version):
	cd /usr/src
	wget http://dfn.dl.sourceforge.net/sourceforge/xmlrpc-c/xmlrpc-c-1.11.00.tgz
	tar xvf xmlrpc-c-1.11.00.tgz
	cd xmlrpc-c-1.11.00
	./configure --disable-cplusplus
	make
	make install

to install libtorrent, follow the next steps, as root:
	mkdir /usr/src/libtorrent
	wget http://libtorrent.rakshasa.no/downloads/libtorrent-0.11.9.tar.gz
	tar xvf libtorrent-0.11.9.tar.gz
	cd /usr/src/libtorrent-0.11.9
	./configure
	make
	make install

to install rtorrent, follow the next steps, as root:
	mkdir /usr/src/rtorrent
	wget http://libtorrent.rakshasa.no/downloads/rtorrent-0.7.9.tar.gz
	tar xvf rtorrent-0.7.9.tar.gz
	cd /usr/src/rtorrent-0.7.9
	./configure --with-xmlrpc-c
	make
	make install
	
-if you don't have a .rtorrent.rc file, create one into your home directory
-you can find an example .rtorrent.rc file here: http://libtorrent.rakshasa.no/browser/trunk/rtorrent/doc/rtorrent.rc?rev=latest
-open .rtorrent.rc, and edit them (for each user)
 -add this line to your .rtorrent.rc "scgi_port = 127.0.0.1:12345" where 12345 can be replaced by your choice, and restart rtorrent
 -if you have more than one user, set a different port for each user's .rtorrent.rc file (be aware, to set different session directories for the users)
 -set your download directory
 -make sure, you have your session directory set and it exists, so rtorrent can continue will remember your torrents after it's restarted
 
now, you can start rtorrent, and on the bottom, you should see something like this: "(20:55:52) XMLRPC initialized with 346 functions."

if everything went fine, extract the rtwi-xxxxxx.tar.gz to some place where your webserver can see it
in case, it's your first install, open the freshly extracted includes/config.php.inc, and edit the next lines:
-$abs_path (the absolute path of your webroot, i.e.: "/var/www")
-$domain (your domain, i.e.: "example.com")
-$site_path (the relative path of the rtwi-xxxx directory, or whatever you renamed it, within your webroot, i.e.: "/rtwi/", if it's absolute path is /var/www/rtwi/)
-$include_path (if you move the includes directory, or eave it untouched, i.e.: "/includes")
-if your php interpreter does not handle .html files (only .php) set the $default_ext variable to "php", and rename the index.html to index.php

adding users:
 -find row 32, and change it:
 -replace "userX" with the actual linux username
 -replace "1234567890abcdef1234567890abcdef12345678" with the sha1 hash of the choosen password for the webui (you can generate the sha1 hash here => http://www.johnmaguire.us/tools/hashcalc/index.php)
 -replace "12345", with the port, you've set in the user's .rtorrent.rc file
 -keep the quotes in the last three steps
 -if you have more than one user, you have to repeat these steps, for each one of them, so you'll get something like this:
	$users = array(
		"user1"		=> array( "pass" => "1234567890abcdef1234567890abcdef12345678", "port"	=> "12345" ),
		"user2"		=> array( "pass" => "1234567890abcdef1234567890abcdef12345678", "port"	=> "12346" ),
		"user3"		=> array( "pass" => "1234567890abcdef1234567890abcdef12345678", "port"	=> "12347" ),
	);

troubleshooting:

-xmlrpc 1.11 compilation stops with some syntax error
-try to configure with --disable-cplusplus

-rtorrent compilation stops with an errer, which says, i have no libtorrent installed (No package 'libtorrent' found)
-find your libtorrent.pc file (try /usr/local/lib/pkgconfig), and set the PKG_CONFIG_PATH environmental variable to it's path (export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig)

-rtorrent compilation stops with an error, which says, my libtorrent's version is an empty string (Requested 'libtorrent >= 0.11.8' but version of libtorrent is)
-upgrade you automake (you need 1.5+)

-i can see the php code in the browser
-you php settings does not allows you to to have a php file named .html - change these settings, or rename the index.html to index.php, and set the $default_ext variable to "php" in rtwi's /includes/config.inc.php
-php modul is not loaded by the webserver, take a look at your webserver's manual, to find out, how to enable it

-i get some php errors about xsl...
-install (or if it's installed, than enable) the xsl php extension

-i get some php errors about xmlrpc...
-install (or if it's installed, than enable) the xmlrpc php extension

-i've set my username and my password in the config.inc.php, ut i cannot log in
-did you use the password?> you need to use the password's sha1 hash (you can generate one here =>you can generate the sha1 hash here => http://www.johnmaguire.us/tools/hashcalc/index.php)
-enable cookies (or at least session cookies)

-i get the "No connection" message in rtwi
-set the same port in your .rtorrent.rc file, at the scgi_port=, and in the rtwi's /includes/config.inc.php at your user's line
-check, if rtottent is listening on the port, you've set (netstat -na | grep 12345)
 -if it is
  -check your firewall
  -recheck the port set in rtwi's incudes/config.inc.php
 -if it is not
  -recheck your .rtorrent.rc - it should have a line like this: scgi_port = 127.0.0.1:12345
  -try to set the scgi port in runtime (ctrl+x, then entre "scgi_port = 127.0.0.1:12345")
   -if rtorrent stops with an error, that says xmlrpc is not supported, configure xmlrpc-c with --with-xmlrpc-c, and recompile

-the add torrent menu does not work (at all - it shows me an empty page)
-your download directory should be in your home directory

bug reports, whishlist, suggestions, anything: ghudiczius@gmail.com

p.s.: sorry, for the lot's of typo, this loosy manual, and my even worse english :)
