I share your concern about GC pauses. LLVM bitcode provides no security guarantees whatsoever though. It has raw unchecked pointers. You can even cast arbitrar

I share your concern about GC pauses. LLVM bitcode provides no security guarantees whatsoever though. It has raw unchecked pointers. You can even cast arbitrary integer values to pointers and dereference them. In PNaCl, security is provided by the NaCl layer beneath the LLVM layer. It's an interesting idea, to have an OS kernel with processes/etc sandboxed from each other with NaCl sandboxes instead of traditional protection mechanisms. I wonder how the overhead compares.