Qt Creator has vertical tabs ("Opened documents" panel) which is way superior as soon as you have more than 3 files open. It's also pretty useless since you can

Qt Creator has vertical tabs ("Opened documents" panel) which is way superior as soon as you have more than 3 files open. It's also pretty useless since you can just <ctrl-k> <first few letters> <enter> or <ctrl-tab> to switch