You only need two files to set up a repository on a server, and only one if you don't want users to be able to add files to the repository.
This file can have just about any file extension, as long as it is text-readable (i.e. can be opened in notepad). The way you share access to this repository is sharing the link location to the file with others, who can then set the repository as their default in their clients. However, users cannot add to this file, they will only be allowed to download from it, which is where the second file comes in.
The Repository File is basically a list of file locations and their names that the client can access them from. The format is as follows:
FILENAME|FILELOCATION
"FILENAME" must not have any spaces in it. So an example would be:
firefox|http://www.mozilla.org/firefoxinstaller.exe
A user connected to this repository could then get this file by entering "get firefox".
This file must be named repoadd.php or else the client will not be able to access it. It must also be in the same location as the repository file. You do not need to share the link to this file, the client only needs the Repository File location. In the repoadd.php file add the following:
<?php
$msg = $_GET['f'];
$ukeyfile = "testrepo.txt";
$fp = fopen($ukeyfile, "a");
$newl = "\n" . $msg;
fwrite($fp, $newl);
fclose($fp);
?>
Change the testrepo.txt to the name of the repo file. And that's it, you have now set up a RapidHook repository.