1. Free Trial License
It has all the functions of the full version, even including video chat and file transfer!
10-concurrent-limit, and a dedicated server is required to host the IM by your own.
2. Free Hosted IM
It's hosted by 123 Web Messenger, free of charge, no connection limit, can be embedded to website, and it provides the basic one to one chat function.
No admin panel, no settings, no user registration, no user database integration, no video chat, friend list can't be saved, text ads can't be removed. Meanwhile, the hosted IM might be shared with some other website which is using the same host name because it is not especially for your website.
3. Paid License or Paid Hosting
Admin Panel, ban/kick, user registration, user database integration, video chat, file transfer, friend list, one on one chat, Windows Desktop Client, add advertising, custom logo and change skin, etc. Professional support, everything you can imagine and NO ads!