The only thing that turns me off to a product more than a poor website is poor English in the documentation. If English isn't your primary language, PLEASE get someone that speaks it fluently to either write your docs, translate your docs, or edit what you've written.
They are nice to write the documentation in poor English, they could launch the product only with Polish documentation and then you would never be able to use it before someones translates it.
While this is true, it's to the detriment of their project not to have at least some English docs. It grants them the largest possible audience[1] for their project. Generating interest in their tool is one of the things that they need to do if they want it to be a successful open source project.
[1]: I guess it's possible that 'Chinese' might be close too, but I have no idea how the different dialects (Mandarin/Cantonese) would affect this.