This site is a bit different from the other sites listed here.
First, the site is hosted on one of epoch_qwert's boxes at home, so the connection is sometimes a bit slow.
Secondly the challenges differ a lot from the usual stuff here;
thebackupbox offers "shell" challenges.
You connect via SSH to the (NetBSD) box and exploit programs to escalate priviledges.
Many thanks for joining us and
Happy Challenging !