NsJail is a lightweight process isolation tool that leverages BPF (Berkeley Packet Filter) integration to enhance syscall filtering, which is particularly useful for environments like online judges where security is a top priority. Users have noted how NsJail's capabilities improve their understanding of Linux kernel features and are drawing comparisons with other similar tools such as Firejail, Bubblewrap, and runc. The discussion also touched on process isolation's potential for further innovations, including a historical feature of 'cryogenic freezing' of processes, which sparked curiosity about its feasibility in modern systems. Overall, there is an increasing interest in enhancing process isolation for performance, security, and other applications.