LE does support alpha. You have to set blend mode to 1. http://www.leadwerks...?title=SetBlend
I have been using the 2d drawing commands to do my interfaces. http://www.leadwerks...itle=2D_Drawing
I have a library that i have written that is about 85% to release an alpha. le_gui is sadly very complex. I am very happy with it but it sits around 1600 lines of code. It supports event propagation, stylesheets, a rich styles inheritence system, z sorting/index, control parenting, render caching, clipping, a good positioning system via top, left, bottom, right and most importantly a nice api. It is not documented and there are no examples so it might not even be worth your time to look at it. If you need an example of some code that will be able to handle complex interactions, it could be inspiring.