Yeah, OpenEXR (http://www.openexr.com/) is a very nice format, well designed and documented, and with an open-source implementation.
Apart from VFX and post-production, OpenEXR has also become the standard file format in HDR applications.
IMHO it isn't mainstream yet because most people don't know what HDR imaging is and why current image formats are inadequate for HDR. For still image editing Photoshop is overwhelming dominant, whereas in VFX pipelines there's a lot of custom tools so you need an open format.
Apart from VFX and post-production, OpenEXR has also become the standard file format in HDR applications.
IMHO it isn't mainstream yet because most people don't know what HDR imaging is and why current image formats are inadequate for HDR. For still image editing Photoshop is overwhelming dominant, whereas in VFX pipelines there's a lot of custom tools so you need an open format.