Tamarin (Adobe + Mozilla Love)

Very exciting, Adobe open sourced their ActionScript Virtual Machine, a “high performance” VM featuring a Just-In-Time (JIT) compiler. They have also contributed it to Mozilla which created the Tamarin Project will eventually be integrated to the core JavaScript engine.

The good news for developers is that they are targeting ECMAScript 4 (which means JavaScript 2), but users should see benefit as well from the expected performance increase. JavaScript heavy pages should really fly due to the presence of the JIT compiler.