This is a much less revolutionary proposal than it may seem. The web already features extensive use of a non-Turing complete language. It's a less-appreciated f

This is a much less revolutionary proposal than it may seem. The web already features extensive use of a non-Turing complete language. It's a less-appreciated feature of SQL, but it makes defense against nasty attacks at least feasible (if not always applied). Another important advantage is query optimization. Programs in non-Turing complete languages can be automatically analyzed, not only to determine their security implications, but also to rewrite them in optimal form. In a good NTCL with an optimizer, you don't care how (in)efficient your algorithms are - they're automatically upgraded to their theoretical fastest speed.