by T. Michael Keesey (

Haeckel is a biological visualization library written in TypeScript and published as JavaScript. It includes functionality for:

  • Modeling scientific concepts such as taxa, phylogeny, character states, stratigraphy, and geography.
  • Processing scientific data (notably calculating morphological distance and inferring unknown character states).
  • Rendering data into charts as Scalable Vector Graphics, using RaphaëlJS.

It is named after Ernst Haeckel, an important figure in the fields of evolutionary biology and biological illustration.


Haeckel is available under the MIT license. For more details, see the LICENSE file.


This project is currently in "alpha" release, meaning it is incomplete and not thoroughly tested. Further documentation will be available at a later date.