The discussion around the SeL4 microkernel highlights its theoretical roots and practical application challenges, revealing a divide between academic interest and real-world usability. Several user comments reflect skepticism about its practical significance, questioning whether it has evolved beyond proof-of-concept implementations. Key points raised include the importance of formal verification of software, the constraints of currently recognized security specifications, and the ongoing reliance on traditional Linux kernels despite advancements in microkernel design. Participants express confusion about the real-world implications of formal proof in software security, suggesting a need for clearer communication about what formally proven software guarantees. There’s also concern regarding the necessity of ensuring that overlying operating systems are verified to maintain the security of the underlying kernel.