The Search for OS GIS Supporting Discontinuous Projections
Discontinuous or Interrupted Projections like the Butterfly Map are certainly exotic. But does that also mean that there are no open source GIS supporting them?
This question on gis.stackexchange.com is awaiting an answer :)
Using Generic Mapping Tools (GMT) it seems relatively easy to create a map showing an Interrupted Sinusoidal Projection. Here’s an example out of their manual (PDF, page 121):