Firejail is described as 'SUID security sandbox program that reduces the risk of security breaches by restricting the running environment of untrusted applications using Linux namespaces and seccomp-bpf' and is an app in the Security & Privacy category. There are eight alternatives to Firejail for a variety of platforms, including Windows, Linux, the Web, Android and Sandboxie. The best alternative is Shadow Defender. It's not free, so if you're looking for a free alternative, you could try SHADE Sandbox or Cuckoo Sandbox. Other great apps like Firejail are Any.Run (Freemium), R&S Browser in the Box (Paid), mbox (Free, Open Source) and WinJail (Paid).