This information should be simple enough to write additions to your php application to provide eZ publish content object information. You could start by writing a cli script to provide the data first in someway as a proof of concept ...
It really depends on exactly what kind of application, how you want access to the information. This specific choice of how you access the information is important.
<b>Just Write the Code ...</b>
If it's compatible php 4.4.x application you should be able to add code to your existing application to provide the eZ publish content to your application.
And there have got to be plenty examples of how to open up and fetch the data you want. I'd search for people back in the day looking to 'export' data ...
<b>PS</b>
I've added an entry to the wiki based on your forum message :) <i>http://pubsvn.ez.no/wiki/en/ez/question_what_documentation_about_ez_publish_do_you_feel_is_missing</i>
<i>no?</i>
//kracker
i am nothing ... <i>14-mansbestfriend_(sole)-dream_i_had_on_my_25th_birthday-cms</i>
how to do a fetch with php <i>http://ez.no/community/forum/developer/how_to_do_a_fetch_with_php</i>
I've added this link and a number of other examples from the forum into the wiki. <i>http://pubsvn.ez.no/wiki/en/ez/api_code_samples#eztoc388_1_1_1</i>
