Jeff Atwood wrote about MeWare, ThemWare, and UsWare.  It draws a useful distinction between the software a lot of us developers use and the software we build for our customers.  Our customer are scientists and lab techs.  They don't spend a lot of time on the 'Net, and for most of them, what they know of social networks comes from their kids. They walk in different circles.

Our customers humble us, because they want to know as little as possible about our software. To them, software is a tool to get their work done, and the best possible tool is one that is invisible in their mind. Success is simplifying their job  and fading into the woodwork (or lab bench as it were).

It's a different software design challenge. How do you make software that is invisible?  We visit customers where they work, watch them work, talk to them, and try to get in their heads. We try to make our software map their mental model of the universe and not force them to adapt to us. We think a lot about making features discoverable. We try to avoid surprises. That's tough when you're also trying to solve hard problems for the user, and finding the right balance is tough work.

That alone makes UsWare fun, but the bonus is that our customers are great people too. They are professionals, they are analytical, and they treat us as partners in improving healthcare. It's a pleasure build software with them.