RealChat was written as alternative to popular "Intranet Chat" (author Alexander Vorozhun) for local networks. With all iChat's advantages, there was some serious disadvantages: weak server side, unstability with big numbers of users, message transfer protocol vulnerabilities.. Author sometime stopped his work on chat and not publish sources for further project development.
RealChat use wide-famous message transfer protocol IRC, have look and functionality similar to iChat, and have some rare features.