SquirrelFish compiles bytecodes from a syntax tree, using a one-pass compiler with built-in copy propagation. The development team claims the speed boost comes mainly from SquirrelFish's ability to ignore redundant nodes, but is also due to single direct memory reads, single indirect branching, and eliminating the syntax tree, allowing the interpreter to skip execution states between syntax tree nodes. The WebKit team admits that the system is in early stages of development, but they expect to have compile-time optimizations and optimizations to the virtual machine engine, before it is ready for mass scale deployment.