Possibly as a result of this, more fans of web serials have decided to create their own, propagating the form further, leading to the number of serious, original works growing quickly. Some serials utilize the formats of the media to include things not possible in ordinary books, such as clickable maps, pop-up character bios, sorting posts by tag, illustrations, and video. Supplementary information is often available on the serial's website, sometimes in the form of wikis that fans of the work help maintain.