Authoring learning content is an area under pressure due to conflicting requirements. Adaptive, templatebased, highly interactive, multimedia-rich content is desired for current learning environments. At the same time, authors need a system supporting collaboration, easy re-purposing, and continuous updates with a lower adoption barrier to keep the production process simple, specially for high enrollment learning scenarios. Other areas such as software development have adopted effective methodologies to cope with a similar increase in complexity. In this paper an authoring system is presented to support a community of authors in the creation of learning content. A set of pre-defined production rules and templates are offered. Following the single source approach, authors create documents that are then automatically processed to obtain various derived resources. The toolkit allows for simple continuous updates, the re-use and re-purpose of course material, as well as the adaptation of resources to different target groups and scenarios. The toolkit has been validated by analyzing its use over a three year period in two high enrollment engineering courses. The results show effective support and simplification of the production process as well as its sustainability over time.