问题:

Say I want to develop a site with some CMS embedded in it - e.g., a Wordpress blog and phpbb forum.

What's the most convenient way to unify the log-in and sign-up process for my site?

Letting users have a different registration process for each part of the site would probably scare any sane user away.

EDIT

I prefer generic solutions, not necessarily for the aforementioned CMSs.

回答1:

Both Wordpress and phpBB3 have OpenID authentication plugins -- you could use OpenID for both.

回答2:

This might be what you want:
http://www.wp-united.com/

回答3:

Usually this is solved by a plugin into one CMS that uses or even syncs the login data from the other system.

For Wordpress / phpbb you might have a look at this

Using the data works, if the system does not need additional user data, so phpBB could not use an external login table because AFAIK it needs extra data for users (such as permissions).

回答4:

I think this is what you want:

http://www.e-xtnd.it/wp-phpbb-bridge/

This plugin is for WordPress, there is no need to create phpBB hacks. You can login once on both software, and also you can use some installed widgets to integrate more options from the phpBB side into WordPress.