A discussion of what parts of the sys module various VMs should be expected to implement has come up on python-dev. I am hoping someone here can let me know what PyPy currently implements. - argv - byteorder - path, path_hooks, meta_path, path_importer_cache, and modules - copyright, hexversion, version, and version_info - displayhook, __displayhook__ - excepthook, __excepthook__, exc_info, and exc_clear - exec_prefix and prefix - executable - exit - flags, py3kwarning, dont_write_bytecode, and warn_options - getfilesystemencoding - get/setprofile - get/settrace, call_tracing - getwindowsversion - maxint and maxunicode - platform - ps1 and ps2 - stdin, stderr, stdout, __stdin__, __stderr__, __stdout__ - tracebacklimit - get/setrecursionlimit - get/setcheckinterval - _getframe and _current_frame - getrefcount - get/setdlopenflags - settscdumps - api_version - winver - dllhandle - float_info - _compact_freelists - _clear_type_cache - subversion - builtin_module_names - callstats - intern -Brett