This is a first for me in all my years of rating message boards, I've never seen a fully bi-lingual community. I love this design and commend you for innovating something like this. I was once on a forum with a friend of mine, his name was Big_Lord, and he spoke Portuguese and English but the forum he was designing was only in Portuguese and only had one form to involve English speaking community. So I couldn't do very much for that community. However, with this design you have two separate communities for each language of speakers and that is very important in this day in age.
Since mi Esponol es no bueno, I will make this rate based solely on the english side, assumeing that the spanish side is equally well developed and maintained.
I like your color scheme, the fact that you're using a phpbb forum makes those things much more intricate and I have alot of respect for people who can perfect things on this system. You seem to have a good handle with graphic abilities too. I am assuming since there are no appropriations stating the skin was developed by an outside source that you or someone on your staff make the skins. Whomever it may be, they do good work and I hope they stay active.
Your activity seems to constantly be fresh which is a good sign of activity on the forum. I assume that you have a good large community with multilingual forums working aside each other. I noticed on the guest friendly forums, you have a little icon indicating that you have guest communication open. This is very well designed on your part. While the image is basic, something like that is very unique to your community. Keep that kind of person-ability up and you will continue to grow.
Other than these things, I feel you have a great community and I hope that you continue to grow. If you can as a final note, try to make a more filling background, it looks great but it lacks on the sides. having a solid background or even adding a sidebar would be beneficial to this community.
If you have any questions or responses to my review, please feel free to reply here or message me. I'm more than happy to discuss things with you.
Kalo
