Omniware : A Universal Substrate for Mobile Code

In this paper we describe Omniware, a system for producing and executing mobile code. Mobile code will be used in next generation Web applications to specify dynamic behavior in Web pages, implement new Web protocols and data formats, and dynamically distribute computation between servers and browsers. Like all mobile code systems, Omniware provides portability and safety. The same compiled Omniware module can be executed transparently on different machines, and a module's access to host resources can be precisely controlled. In addition to portability and safety, Omniware has two unique features. First, Omniware is open. The Omniware virtual machine, OmniVM, supports standard programming languages, enabling Web developers to leverage the vast store of existing software and programming expertise. OmniVM was designed to be a straightforward compilation target for a large variety of source languages. Second, Omniware is fast. We evaluate Omniware under the Solaris 2.4 operating system on a SPARCstation 5 using eight C benchmark programs, including five programs from the C SPEC92 benchmark suite. We evaluate the performance of Omniware in two ways. First, we show that Omniware modules can be represented compactly, reducing the space consumption compared to standard programs by an average of 38%. Second, we show that Omniware modules execute at near native speeds. Including the runtime overhead necessary to ensure that Omniware modules are both portable and safe, our benchmark programs ran within 9% of native performance.