As an active developer of the OpenLayers mapping library, I have been working a lot on performance improvements in the rendering pipeline. Performance is usually good, but there are corner cases where the user experience is negatively affected by an unresponsive user interface. There is a new browser technology, OffscreenCanvas, which allows rendering in web workers that run in parallel to the main thread. Unfortunately it is not widely supported in mainstream browsers. In this post, I am going to show how rendering performance in OpenLayers could benefit from OffscreenCanvas. Continue reading →