eulerr is an R package that generates area-proportional Euler diagrams to display set relationships (intersections, unions, and disjoints) with circles. Euler diagrams are Venn diagrams without the requirement that all set interactions be present (whether they are empty or not). That is, depending on input, eulerr will sometimes produce Venn diagrams but sometimes not.
With three or more sets intersecting, exact euler diagrams are often impossible. For such cases eulerr attempts to provide the best approximation possible by numerically tuning the circles positions and radiuses so that the sum of absolute errors is minimized.
The source code is avaiable on GitHub where you are welcome to contribute to the ongoing development of eulerr.