Find someone to teach. Instead of you writing the fun software guide them to develop the fun software.

Do something completely different. Don't code for a year.

If you loved it once, it will come back to you.

Just find another creative outlet. When I can't come up with a solution to a design I'm working on, I just pick up my guitar and play for a bit. Generally the excitement from that exercise gets me back in the mindset to work on the design I'd left. Of course your thing doesn't have to be music. Just explore different topics of interest and see what sticks.

I think if you're burned out and try to force fun, it won't happen. The fun comes from following inspiration. Like recognizing a pattern in life and thinking 'I know how that works' and playing with some code as a reaction to that inspiration. Not because you think you should or associate yourself with being a programmer or whatever else, but because it just seems like the most natural way to carry on approaching the thing that sparked your interest.

That sounds like an impossible question to answer, without a deeper understanding of who you are, your life experiences and what you've noticed has driven you.

Doing something that will help a bit and then returning to what originally burnt you out will not work IMHO.

Fresh creative work is something that enables you to make a break with your history.

You have to move on.

The thing that excites me is when I come to something I don't know how to do, and don't think I could ever know how to do, and then I teach myself it.

I don't know what kind of software you write, but if it were me, and I got tired of writing software for the web, I'd try to pick up writing graphics, or writing native mobile.

Try shifting focus from programming to purpose. It's far easier to "burn out" on code than it is on the ends that programming serves: success of a company, entertainment of users/players, advancement of science, ...

see how other creative people do it.

http://www.amazon.com/The-Creative-Habit-Learn-Life/dp/07432...

from amazon "Twyla Tharp, one of America's greatest choreographers, began her career in 1965, and has created more than 130 dances for her company as well as for the Joffrey Ballet, The New York City Ballet, Paris Opera Ballet, London's Royal Ballet, and American Ballet Theatre. "

Well, if you're approaching a senior age, and you've been recognized for your fundamental breakthrough scientific research in computer science - that you made while having fun writing software - maybe you should think also about writing a book, besides perhaps taking that academic position you rightly were offered.

Do you explore/holiday much? (Not a sit-by-the-pool holiday, but something a lot more involved.)