In this thesis, I investigate the style guide processes in Telenor, a Norwegian mobile operator that is one of the largest in the world. The ‘style guide problem’ is well known, and it is difficult to handleguidelines, principles, and conventions in any organization. Most people agree that style guides are important to ensure consistency and quality in applications and various content utilizing style guides. No dedicated tool exists to produce and manage style guides in Telenor, but there are many general tools available. I argue that these general tools do not fulfill the requirements of a style guide process in Telenor. With ‘development research’ as my research approach, I gathered user requirements from users in the company. The result became a prototype of the style guide production and management tool, developed through multiple iterations in a development cycle. The purpose of the tool is to make the production and management of style guides dynamic. The tool was evaluated using expert walkthroughs and individual heuristic walkthroughs with real users and humancomputer interaction (HCI) experts. The evaluation is the foundation for future development of the prototype, and research on the subject. I argue that my style guide tool is the solution for the style guide problem in Telenor, and can be used in any organization. The tool is a web application, using rich internet application (RIA) functionality. It is simple and easy for style guide developers and end users to utilize. It provides functionality such as revision handling, templates, approval, and reviews. The tool provides enhanced user experience and usability, and improves the users’ workflow in style guide processes. Altogether, the tool makes people work together in a dynamic collaborative environment that supports usable, accessible, and consistent style guides.