For some time now it has bugged me that there are no interpolation plugins for Leaflet. I believe that future mapping and GIS tasks will increasingly be performed in the cloud or on the fly in web applications, therefore an IDW plugin can become quite useful for Leaflet. There are a few heatmap plugins, but these do not always serve the purpose of the map. If for example one was to make a map with continuous temperature or wind interpolation, heatmaps are not the right choice. One of the more simple interpolation algorithms is the inverse distance weighting algorithm or IDW.