morbidissimo

Checks a folder (e.g., ./scripts/) for files *.py.
If file contains a function run(), this is imported and executed.
At a fixed interval, the function is run again (if the last call has finished). If it is still running, it will not be started a second time (i.e., continuous scripts also work).
If a file's mtime changes, its potentially running function will be killed, the script reloaded and executed again.

MorIOC

A trivially easy to use softIOC:

Uses pcaspy (in a slightly unintended way).
serve (output) PVs and host (input) PVs:

with MorIOC("mtest") as mor:
    while True:
        # serve MTEST:RAND1 and MTEST:RAND2
        # holding a random float and a random int
        mor.serve(
            rand1 = random(),
            rand2 = randint(10, 100)
        )

        # host MTEST:BUCKET
        # can be filled from external via caput
        # get current value
        # serve MTEST:DOUBLED holding the doubled value
        mor.host(bucket = int)
        value = mor.get("bucket")
        mor.serve(doubled = value * 2)

        sleep(0.5)

PV's data type is inferred from the value.
Currently supports Python scalars (int, float, str), sequences (lists, tuples, etc.) as well as numpy arrays and scalars.
Alternatively, an object-oriented interface exists:

with MorIOC("mtest") as mor:
    pvo = mor.PV("chan-PV-out") # creates MTEST:CHAN-PV-OUT
    pvi = mor.PV("chan-PV-in")  # creates MTEST:CHAN-PV-IN
    img = mor.Image("chan-Image")
    # creates MTEST:CHAN-IMAGE:FPICTURE, :WIDTH, :HEIGHT

    while True:
        val = random()
        pvo.put(val)

        val = pvi.get()
        print(val)

        val = np.random.random(200).reshape(10, 20)
        img.put(val)