After contacting Josiah Carlson, author of the activestate patch for asynchronous I/O in subprocess.Popen, he was more than happy to release the code into the public domain so my license conflicts with his patch are now resolved. Some of the tests I wrote for his patch have failed and he agreed to take a look at what I wrote to help me get the tests running properly.
Upon running my tests, he realized that pywin32 is not part of the standard library which complicates my project a bit as far as Windows is concerned so I am now looking for alternatives to Josiah Carlson's asynchronous I/O patch for subprocess.Popen on Windows. If I cannot find an alternative, I will be using cTypes with the parts of Mark Hammond's code that I need, license permitting. Any suggestions are greatly appreciated.