Zendesk for WordPress allows you to bring your helpdesk, powered by Zendesk, into your blog or site. Here's an overview of all the features:

Single sign on with Zendesk's Remote Authentication

Have a healthy user base already? With Single Sign On, your users won't have to login to Zendesk to submit tickets, check their progress or comment in community forums.

When users try to login to Zendesk, we'll ping your WordPress site to see if they're already logged in, and then sign them straight into Zendesk without them needing to register or set a new password. It's 100% secure, too!