Lin, I looked at the website (link you provided) - thanks for making this known - never heard of it before. However, I didn't find the website all that informative. For example, not clear whether it supports 16 bit image editing and how it handles colour management, supports duotones, quadtones, layer masking, etc., etc. What is your experience with it in these areas?
Yes, they haven't yet written documentation (will be in many languages) but it does support 16 bit editing. I can't say about color management, but the entire code is 1.5 megabytes and you can download and try it free and experiment. As with their other programs, it will undergo constant improvements and upgrades will be free for life so nothing to loose by testing it.
Hopefully there will be documentation soon - but it's a cooperative effort getting docs written in so many languages and the developers are Russian and though they speak English need help with subtle verbiage.