Python already has several ways to run programs concurrently — including asynchronous functions, threads, subinterpreters, and multiprocessing — but all of those options have drawbacks of one kind or another. PEP 703 ("Making the Global Interpreter Lock Optional in CPython") removed a major barrier to running Python threads in parallel, but also exposed Python programmers to the same tricky synchronization problems found in other languages supporting multithreaded programs. A new draft proposal by Mark Shannon, PEP 805 ("Safe Parallel Python"), suggests a way for the CPython runtime to cut down on concurrency bugs, making it more practical for Python programmers to use versions of the language without the global interpreter lock (GIL).