What would you write if this were a question on an application?

Whatever you write in this section, make it relevant to the job you're applying for. If the job is calling for programmers with experience in Java and C++, then you should write something here about how you write programs for fun, or that you write things that have been used by friends or family. Those are the things that aren't normally captured in the standard question set (those usually focus on paid work). Definitely stay away from political, religious, or questionable activities and topics - stick to the job itself and activities that are directly related to the position. The job description is a great reference for something like this - use key words from the description in your response.