Abstract. Collaborative writing and editing typically use annotations to coordinate edition tasks, comment the content, add relevant references, or clarify confusing content. Despite that wikis are among the most widely used hypertext systems for performing such collaborative activities, they have little support to annotations. In this paper, we propose to use spatial hypertext layers as the solution for the management of annotations in wikis. We have extended ShyWiki, a spatial hypertext wiki environment, with Multilayer Superimposed Information features. In addition, we present the results of a study that shows the value of spatial hypertext layers for locate, organize and group annotations in interest groups under a wiki interface.