AutoIt is freeware, but it is not open sourced. Open sourced means the source code is available to the public. That was true back in the early 2000s, but they changed it to being closed sourced. Only developers have the current source code.
If you want to support this language, I suggest you look at unfilled needs, most likely UDFs that no one has produced before. Or updating outdated ones that are no longer supported (I know the Firefox UDF needs some updating). Also, you may want to post some of your work in the example scripts section. This will demonstrate your abilities and other people will point out more efficient ways of doing things.