WowShack | Indoensia-Related Content Worth Sharing
The map was created by Muturzikin. You can view the rest of his creations at his website here.
According to the site, "These maps display the ethnic and linguistic complexities in some parts of the world that are too often ignored or discarded by nationalists. We seek to preserve the integrity of the area in which the language or dialect is spoken, even where this crosses international borders".