MAML is part of a new approach to help in Windows Vista. This approach is both more integrated with the software and more focused on user tasks. MAML provides a structre in which you can write user assistance information, which can then be presented to the user in a variety of locations.
An example of help using this schema (http://schemas.microsoft.com/maml/dev/2004/10) can be found on the Microsoft Office Online Assistance. Additionally, if the user chooses to get the latest online content, that content is downloaded to the local machine as MAML and transformed at runtime into HTML for display, just as the local content is.
MAML Topic Types
The following types of topic are currently in use in the new MAML based Office Online pages:
Training: to learn more about using programs, focus on features or activity areas and allow to suggest best practices. Courses are self-paced, and include graphics, animation, audio, and practice sessions for hands-on experience. They have an inherent browse sequence
Article: up-to-date information in the form of how-to, and tips information.
Topics :conceptual information about functionality and theory behind features.
Discussion: online Community where you can interact with fellow users, get your questions answered, share ideas, and learn more about products and technologies that interest you.
–Vista Help Technical Overview