Java Telnet chat/bbs Server

I need to run a chat and file server over telnet. simple interface, but quite clever. Needs to run on OSX and/or Windows, and i must be able to compile and make changes myself on a standard install of xCode 2. - colour text (detect, if not usable, then dont include) - log in / sign up feature. - profile for each user - chat room(s) and IM feature. - ability to upload and download files. (and set to be public or privite) - must log ALL activity to date-named logfiles. - admin features including account editing - MUST be VERY secure - INVITE ONLY ( Each user gets one invite to use, so when you sign up, you enter the user's name who invited you, and a password they setup... only that way can you sign up. It will oviously need a database for the backend. mySQL i think would be best.. but is up to you. This will need to be built using a standard install of xCode2.0 for OSX. SQL scripts, if needed, will also need to be provided so i can get everything setup.