I'm a Mac & Windows software developer, and am interested in porting some of my programs to Linux. But, it seems like almost all programs I come across are open source/free. I know there are some closed-source apps out there, but even though they're closed, most look to be free as well.

The trend seems to be (from what I observed anyways) most Linux software is free, but people pay for the support - like Redhat (again, I think this is how it works). I'm looking to go the normal sales route, where I sell the actual application itself and of course some support comes with it, but that's not the main cost of the app - the program is.

Is this "allowed" in the Linux world? Or is this taboo. Are Linux users not used to/willing to pay for software? It'd be a niche product, so it would fill a need, but again, maybe users aren't going to pay for it - and I have to look at it from a business perspective. Any insight would be great. Thanks!