A Case for Language-Based Protection

The use of language mechanisms to enforce protection boundaries around software modules has become increasingly attractive. This paper examines the advantages and disadvantages of languagebased protection over more traditional protection mechanisms, such as standard virtual memory protection hardware, software fault isolation, and capability systems. Arguably, state-of-the-art language-based protection is more flexible and as safe as these other mechanisms. Two major remaining issues are the performance of language-based protection, and the management of resources. Regarding the latter, techniques to build an operating system kernel capable of managing resources and revoking rights are presented.