When comparing Trillian vs The Lounge, the Slant community recommends The Lounge for most people. In the question“What are the best IRC clients for Windows?” The Lounge is ranked 14th while Trillian is ranked 21st.
Ranked in these QuestionsQuestion Ranking
Pro In-house server support
You can set up a dedicated server to hold your communications. Great for businesses that want to build their own infrastructure.
Pro Multiple networks in one place
Among them Yahoo!, Facebook, Skype, Google, AIM, ICQ, XMPP, MSN. You can have multiple accounts associated with each service.
Pro Group chat
Trillian to Trillian group chat is available.
Pro Highly maintained
You can see the activity here. For example 62 pull requests were merged from 2018-02-17 to 2018-02-24.
Pro Hosted on the web
Con Supports all dead services.
Con Server, not an application
This is a server, not an application, so there's that extra bit of overhead.
Con Uses NodeJS