On his blog today, Vinu Thomas looks briefly at one of the compiler options for PHP developers - the Roadsend Compiler.

Finally an open source PHP compiler ! Roadsend was perviously available as a commerical compiler for PHP with prices starting from $129. They seem to have shifted to the OSS model recently, giving free professional licence to their older compiler while they're working on releasing the precompiled versions of their open source code base.

He also links to a community site that offers the latest news about the project, some good places to start if you're just picking it up, and the timeline/roadmap for how things will progress.