Just looking at the code, I wondered what the Moose was doing. It turned out the answer was "nothing". It took only a few minutes to remove everything to do with Moose from this module and give it a simple procedural interface:
What is the function of Moose in this module? I think the other reviewer was right to be a bit angry about this unnecessary dependence. Although I wonder if that guy really needs to romanize Lao, or if it is just some kind of grandstanding using this module to attack Moose rather than write a review of this module itself. If you really need to romanize Lao and you hate Moose, it's pretty easy to get the functioning bits out of this module. No point in bashing this, and it's a bit cruel towards this module's author, who seems to be the only person in the world to have written free software to romanize Lao.
About the module itself, I am totally unqualified to pass comment. I noticed that when I tried the above CGI program on the Wikipedia page about the Lao language, there seem to be quite a few different forms of Lao romanization. If this is just one of them then maybe its name should reflect that, in case someone wants to also provide all the other forms of romanization.
Anyway I think the other review is a misuse of cpanratings so I will give this module five stars to compensate for the other silly review.