Zxchat Server question

Hi Zextras

I am a fan of zxchat, I recently been appointed to work on giving our zimbra 8 an IM service. With that said I suggested my boss to use zextras.. He said that it is paid and we can't use it... I have installed ejabberd tried jwchat, ijab, candy and jappix. But they don't qualify for my boss' requirements. My question is can I and is it legal to use zxchat and use ejabberd as it's IM Server? If yes then how? Thanks guys.