Use Horde Groupware if you want an installer. Also duplicate of request #82.

After having gone through setting up horde3 I'd suggest a basic kind 
of installer when horde is started for the first time. Either let the 
user enter a few basic things about the specific installation (like 
paths) or check things and give feedback (like you do in your test.php 
script already).



Difficulties in setting up a system will distract many potential 
users. I managed, tough :) but only after tiring googling just to find 
out that the cookie path was not correct.



All the best for your project!



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