Silverkool wrote: Hello just want to know if i use CB in a commercial proyect do i need to pay ?

Community Builder is GPL.
You can use it anywhere you want.

You cannot remove any copyright statements from the code.

Advanced Members are authorized and given instructions on how to remove the About menu item from CB User profiles.

Silverkool wrote: So i cant remove the normal about cb in profile ?

CB is free and the reason it is still free is because Advanced members, Professional members, donations, etc fund the effort of development, hosting, new releases, security audits, forum support (like this post), etc.

People seeing the about CB menu on a website may in fact visit Joomlapolis and also download free CB and may also choose to become Advanced / Professional members, this helping fund the effort. So the reasoning is you can use free CB on your website in exchange for keeping the frontend copyright statement thus indirectly helping the effort by perhaps persuading others to become supporters.

Hopefully the reasoning is clearer now.

So, answer is: No, you are not authorized to remove the About CB menu unless you become an Advanced member. Then you can remove this menu from all your websites.