scorecard:

• Safety: python is runtime-safe. System safety is in development.
• GUI: several GUIs have been glued into python: X/Motif, Mac Toolbox, MS Windows MFC, a cross-platform thingy called stdwin, and recently, Tk. Grail uses Tk.
• concurrency: there are thread packages available, but they're not entirely stable. Grail doesn't use them.
• Type system: Smalltalkish, with multiple inheritance and some "primitive" types that can't be subclassed.
• Module System: ala Modula-3. This is a real strength of python for mobile code: the python developer community has experience using well-separated modules collaboratively to build systems.
• Exceptions: ala Modula-3.
• FFI: reference counting on objects makes it somewhat painful. Otherwise, very clean and extensively used.
• RPC: flatten/serialize support in recent releases. ILU support is straightforward and stable.
• IPR: python is distributed under an MIT/X/Berkeley style copyright.