Hello,
If I want to change/add new external login system how can I do that? I found something about lib-auth.php which I can provide my external app authorization - is this true? Can I have an example of that file?
My company wants to integrate zenPhoto with our user management system to operate on it. Is this possible?
lib-auth.php is in zp-core of your Zenphoto installation. Note that the coming 1.3 release changes how that is handled in 1.2.9 (search the forum about).
It is generally possible but of course since we don't know anything about your management system so you will have to find out that yourself.