Prelight 5.0 for Mac was available as a free download on our software library. This software for Mac OS X was originally developed by FilmLight Ltd. Prelight for Mac is categorized as Design & Photo Tools.
From the developer:
Prelight is designed to allow a Director of Photography (DoP) and other creatives to freely author, apply and modify looks. Prelight On-Set provides the full product functionality that you would need for use on production - including exporting 3D LUTs, support for driving LUT boxes and live SDI input - as well as, of course, all of the features provided with the free Prelight licence.
You may want to check out more software for Mac, such as QuickShow OSX, Stone Studio or PhotoDesireeExpress, which might be related to Prelight.