Alternative IDE for compiling and running arduino code?
You can use any C++ IDE you like, best when bundled with a compiler, for example Code::Blocks. Assuming you're using Windows: A combination of a decent editor like Notepad++ and some good compiler chain like MinGW will do, too. If you absolutely have to you could also use MS Visual Studio, I don't bother.

Then create standard console programs with this main():

void setup();
void loop();

int main()
{
    setup();
    for (;;)
    {
        loop();
    }
}


And append your hardware-less Arduino code.