imglib2-ui now supports adaptive multi-resolution, multi-threaded rendering which makes everything much much more interactive.
I put a lot of effort in documenting everything. A (slightly simplified) UML class diagram can be found in /ui/doc/
If you used imglib2-ui before, your code should continue working or require only minimal changes. For examples of how to use, have a look at the interactive examples (interactive.MandelbrotRealViewer2DExample etc). They all have been updated to use the new imglib2-ui. If you run into trouble updating your code, please let me know!