Yes, that's mostly true. In early days, native TCP/IP stacks wasn't good at handling so many simultaneous connections as ICQ needed to handle. So AOL just wro

Yes, that's mostly true. In early days, native TCP/IP stacks wasn't good at handling so many simultaneous connections as ICQ needed to handle. So AOL just wrote their own TCP/IP stack (I think they used this implementation not only in ICQ). In modern days, it's legacy. I think they already removed this stack since I left company.