For a long time it opened a new window for each conversation so you could have a few going at once and see them all side-by-side. At some point tabbed windows

For a long time it opened a new window for each conversation so you could have a few going at once and see them all side-by-side. At some point tabbed windows became standard, but I'm pretty sure most clients like Pidgin will still give you the option of separate windows.