Hi, I was thinking why not have a separate file for all the proposed optional meta-information (in particular interfaces, static types)? Something along the lines of IDLs in CORBA (with pythonic syntax, of curse). This way most of the benefits are retained without "contaminating" the actual syntax (dare I be so pretentious to even hope making both sides happy?). For the sole purpose of illustration, let meta-files have extension .pym and linking to source-files be name based: parrot.py parrot.pym (parrot.pyc) With some utilities like a prototype generator (to and from meta-files) and a synchronization tool, time penalty on development for having two separate files could be kept within reason. We could even go as far as introducing a syntax allowing custom meta-information to be added. For example something akin to decorators. parrot.pym: @sharedinstance class Parrot: # Methods # note this are only prototypes so no semicolon or suite is needed @cache def playDead(a : int, b : int) -> None # Attributes @const name : str where sharedinstance, cache and const are custom meta-information. This opens up countless possibilities for third-party interpreter enchantments and/or optimisations by providing a fully portable (as all meta-information are optional) language extensions. P.S. my sincerest apologies if I am reopening a can of worms here