This may be in the wrong forum.

We have a site that's set up basically like this:

- Blog subdomain, account required to manage subscription
- Forum subdomain, account required to post
- Store subdomain, account required to buy
- Auto listings subdomain, account required to list for sale
- Property listings subdomain, account required to list for sale

You also need to provide an email address to subscribe to the site newsletter, and to send forms throughout the site, but those are not a concern.

How can we allow the user to sign in once for all the subdomains listed above? I saw someone in a forum somewhere say that it's not worth the trouble to do this, but we feel that all these user sign-ins clutter the experience. I've seen various SSO systems but I'm not sure if they're what we need.

What backend are you using for each section? i.e. Wordpress for the blog? phpBB for the forum?

Blog - b2evolution
Forum - Vanilla
Store - PrestaShop
Auto listings - Open Auto
Property listings - Open-Realty

Do you mind if I ask what your URL is so that I could take a quick look at it?

Well after looking at all the different items on the site, it's a possibility but it would involve looking at each sections login information and then finding something common to allow a global login.

What login information do you mean - where should we look? They all have MySQL databases with tables named something like "user", they all request an email address and password but I think the differences start there. Thanks for your help.

Well do each one ask for a username or email to login with?

They all have an email address and password in common. User name, first name and last name are needed sometimes.

Blog (b2evolution) - user name, email address, password
Forum (Vanilla) - user name, email, password
Store (PrestaShop) - email, password (and first and last name, not very important)
Auto listings (Open Auto) - user name, email, password (and first and last name, not very important)
Property listings (Open-Realty) - email, password, first and last name (it appears, though there's a problem with our template and I can't see the sign-in)

and I forgot to mention
Subscription to site mailing list (poMMo) - email (name is optional and we've preset it to "Subscriber")

Seeing that all of them have email and password in common, you would need to do some of the following.

1) Create a user registration page that would take all the info provided and put the information into each of the databases to create user for each section.
2) You would need to create a login page that could pass the info to each section in the background and automatically log the user in.

Quick question? Did you happen to give Wordpress a look before you started this? Quite a few of these things I have setup under the same wordpress database.

Thanks! We're working on that now, and so far we can get the information into the different tables but when you go to sign in at one of the original sign-in pages it says you can't sign in even though your user exists. We think it's because the password isn't encrypted like the others when it goes through our form, so we're working on fixing that. I'll post when we make progress.

Wordpress was our blog before we found b2evolution, but we wanted a specific site layout and found it easier to integrate b2evolution than Wordpress. We wouldn't use Wordpress as a CMS if that's what you mean.