I just googled and looked up LightZone. It looks like abandon-ware. Even their website hasn't been updated since 2014. Meh!!!

For Macs, there really isn't a decent LR alternative that doesn't cost as much or more than it does. LR is well worth the price.

The old saying "you get what you pay for" rings true. A lot of people these days want freeware, but I've yet to find much of that that is worth even installing. I prefer to buy good software that is well maintained and supported. A lot of the freeware is either abandoned or developed/maintained by a committee, and as such is usually a mess to run.