More details on the design process are available here: http://www.chromium.org/nativeclient/pnacl/stability-of-the-pnacl-bitcode-abi http://www.chromium.org/nat

More details on the design process are available here: http://www.chromium.org/nativeclient/pnacl/stability-of-the-pnacl-bitcode-abi http://www.chromium.org/nativeclient/pnacl/stability-of-the-... (there's a link to a nicely formatted PDF in the bottom). TL;DR: a lot of thought went into it :)