The Olark module provides some simple integration between the Olark live chat service and Drupal. The module also provides a Context reaction to allow you to add the code using more complex Context-based rules, such as adding the code at specific paths, for specific roles, or other criteria. For instance, you could only show the Olark chat on the home page to anonymous users.
In addition to adding the Olark code to your page, the module also tells the operator whether the user is logged in and if so, what their username, email address, and user page are.
Drupal 8 version
The initial port to Drupal 8 has been created. The only feature that is missing is the context plugin feature. Please if you use that feature, help port it.