The most-deployed interpreter, MRI 1.8, doesn't compile to bytecode, so it's not possible for there to be a general system which does this. HOWEVER, I would su

The most-deployed interpreter, MRI 1.8, doesn't compile to bytecode, so it's not possible for there to be a general system which does this. HOWEVER, I would suggest that your fundamental assumptions are wrong here. Without a cache, PHP has to re-interpret the source files for every single request. That's not how Rails works: the code is parsed once at server startup (or the first time it's used, depending on which part of the code you're looking at) and reused in the same process for subsequent requests, so there isn't a per-request parsing cost. As ever, benchmark and profile before making optimisation assumptions.