We begin this chapter with a discussion of the history of ICBT and its roots in bibliotherapy and computerised CBT. We then provide a brief description of one way of administering guided ICBT, including the role of the therapist and data security issues. This description is followed by examples of conditions that are not covered later in the book, such as specific phobias and addictions. We end this chapter with a discussion of technical developments, cost-effectiveness and implementation.