I would like to develop a cross platform application, i'm not sure which is best to use for a desktop application
Microsoft Silverlight
Adobe Air
Java? (don't want to do this)
Firefox Add-On?
I would like to develop a cross platform application, i'm not sure which is best to use for a desktop application
Microsoft Silverlight
Adobe Air
Java? (don't want to do this)
Firefox Add-On?
We're doing x-compiled Silverlight / WPF. Working well so far...
I think Adobe Air is good option.
Obviously you need to consider which platforms to support, if your target is Windows and Mac, you should consider Silverlight as an alternative. I'm working on a rich app to manage books, videos, games and more. My app is built on Silverlight 4 and will be optimized for running both inside the browser and out-of-browser. With Silverlight 4, you have the ability to make custom chrome-windows, without the standard border.
Silverlight and Flash are probably your best two alternatives, but remember that they are resource intensive. Some of the more popular Adobe Air apps hogs memory from the computer.
You need to consider your own personal skillset, which programming languages are you familiar with? If you already know a language, it will take less time to learn the UI-framework with your platform of choice. If you need to learn both the programming/scripting language and the UI-framework, you will likely be less productive, at least in the beginning.
There are quite a few options available for you, but your choice may depend on how complex your desktop application is:
Don't discount QT, wxWidget, Tcl/Tk, and a slew of other cross-platform GUI toolkits out there.
Since you mention c#, you can create desktop GUI application in Mono c# Gtk that can target both windows and linux.
For more info checkout this