Has anyone here used the GTK+ library or any of its bindings (I am considering the .Net/Mono binding)?
I have been poking a little into it since we have to develop a cross platform desktop application.

So far the experience has been pretty alien, and the documentation online cryptic, fragmented (across the different bindings), and sparse (official documentation pages do a worse job than not existing at all).

I am hoping someone would have had a nicer experience than this so that I may continue my diving into it with higher hopes.
Well the only experience I had was through Glade and truth be told, I did not like it one bit.

My feelings towards GTK are woozy, 2.x is just terrible, 3.x is barely supported with no mono or python bindings yet (Unless its available and i haven't seen it yet).

On the other hand, I haven't had the pleasure of dealing with adobe air but I've seen nice apps built using it

http://balsamiq.com/products/mockups
http://www.tweetdeck.com/desktop/

Would you give it a try?
Someone else is already considering Actionscript/AIR and Flex on top of it as well.
I am starting to better get the hang of it, but I still don't enjoy it. Too much development friction. I can only wonder how they developed MonoDevelop on top of it.
Jumping over to what the Java world has to offer :)
The only drawback of adobe AIR is the lack of custom installation. You are tied to adobe's installer which is really really basic. It just puts all your resources in one executable. Consider having a 600mb application which has a lot of resources like images and audio files, it takes around 10-15mins to load into memory then run (the application would stop responding for that duration). I have failed to find a solution for large applications.
Other than that, programming using flash builder 4.5.1 is a lot of fun...
@ZeRaW: A rather convoluted solution to the AIR problem would be to create the application as the installer itself? Have you considered that?
When you publish an AIR application you get a .air file which cannot be run it needs to be installed then the user can run it. So that is not feasible unless you want the user to install an installer that installs the application and then again the full install + app will be bundled in one air file.
Adobe had yet to solve this issue.
@ZeRaW: Have you tried WPF yet?
Wpf is not cross platform so i have not gotten into it yet.
Unless you mean silverlight but can you package a silverlight solution as a desktop application (like in Adobe Air) and have access to OS features...
ZeRaW wroteWpf is not cross platform so i have not gotten into it yet.
Unless you mean silverlight but can you package a silverlight solution as a desktop application (like in Adobe Air) and have access to OS features...
Oh I missed the cross-platform requirement. Silverlight is actually a very decent platform, but very limited compared to WPF. It has a lot of security related restrictions (including manipulating files on the local machine) but with the user's approval, you can run a SL application with elevated security as an "Out-of-Browser" application which is more or less a desktop app. I haven't tried this before and I'm not aware of details and the restrictions applied to out of browser SL apps, but I guess it's worth giving it a shot in your case.
I have been poking a little into it since we have to develop a cross platform desktop application.
Well how about Java SE?
AymanFarhat wroteWell how about Java SE?
That's what he's currently investigating.
@AymanFarhat: I started reading on what is available for the JVM, seems AWT, SWT, and Swing. I excluded AWT early on since it's the oldest and most feature-free.

The choice between SWT and Swing to start with isn't that clear. I like the fact that Swing is MVC-based (original MVC, not web MVC).

I like the fact that SWT uses native OS widgets so that applications will use and look like they've been built specifically for the desktop they run on. Swing instead renders its own controls and emulates underlying OS features. This is all still literature, I have yet to give it all a go.
gtk+ 2.0 has c# bindings, java bindings, python bindings, etc..
one of the major gtk-sharp applications is banshee.
arithma wrote@AymanFarhat: I started reading on what is available for the JVM, seems AWT, SWT, and Swing. I excluded AWT early on since it's the oldest and most feature-free.

The choice between SWT and Swing to start with isn't that clear. I like the fact that Swing is MVC-based (original MVC, not web MVC).

I like the fact that SWT uses native OS widgets so that applications will use and look like they've been built specifically for the desktop they run on. Swing instead renders its own controls and emulates underlying OS features. This is all still literature, I have yet to give it all a go.
I see, I think Swing is very good and yes AWT is outdated and quite limited. As for SWT I never tried it, I will look into it.
mmm is your team good with java?
I think it will come down to which one is you or your team more flexible with.
Java or AS3?
Additionally what does your application do?
Does it depend on OS features, etc
Or is it just displaying info...
Additionally i am on vacation but i think i found a solution to the AIR installer.
Well the team doesn't currently have any Java experience. The AS3 experience is concentrated (in the eyes of management) in another team. (I am involved with both for the matter of fact).

Update about GTK#: I got it running well on Windows, used their TreeView (which is a GridView, Tree, ListView all in one), filled data using SQL, created some form for editing and insertion. It all goes well and fine. Apparently there's also some Databinding plugin library in development for GTK#.