OpenEXR is an HDR image file format featuring:
Support for 16/32bit float and 32bit integer pixels
Multiple lossless compression schemes
Support by all major compositing packages
Storage of multiple, arbitrary channels in a single file

Our suite of plugins provides complete support for OpenEXR in LightWave 3D
Standard image loader and saver supporting RGBA
Image filter plugin to save arbitrary buffers
Limited region support and much, much more...

We are still in beta, but we will make it until the end of August!