kieler/elkjs: ELK's layout algorithms for JavaScript

The Eclipse Layout Kernel (ELK) implements an infrastructure to connect diagram editors or viewers to automatic layout algorithms. This library takes the layout-relevant part of ELK and makes it available to the JavaScript world. ELK's flagship is a layer-based layout algorithm that is particularly suited for node-link diagrams with an inherent direction and ports (explicit attachment points on a node's border). It is based on the ideas originally introduced by Sugiyama et al. An example can be seen in the screenshot below.

Note that elkjs is not a diagramming framework itself - it computes positions for the elements of a diagram.