I've been developing Windows based applications for a long time and most of my present clients still desire a desktop or client/server Windows application. Is it possible to use Ruby for such applications as opposed to its primary purpose of being a Web-programming language?
Yes, you can. Ruby is a full scripting language. You might want to start with the Ruby language homepage to see the capabilities and libraries that are available.
However, just because you can doesn't mean that you should. Before jumping in and using Ruby for a project, see if Ruby can give you things that other languages can't or if there are any disadvantages to using Ruby.
On a mac, you can use the Ruby Cocoa lib to create (what appear to be) native applications. If you want something more cross platform then you might consider a wrapper like shoes or qt.
The Qt toolkit seems the most popular way to do it. The website is http://www.darshancomputing.com/qt4-qtruby-tutorial/
I'm currently writing a little app in a wrapper called Shoes. This seems to make it as simple as pie to create windowed apps in ruby. http://shoes.heroku.com/ is the website.
At the moment Shoes looks suitable only for small personal apps. I say this because it's author recently went AWOL and it's not clear whether it will be developed further. I'm using it to write a game log parser to generate statistics from a flight sim. It's ticking along nicely.
Ruby is a general purpose object oriented scripting language. Ruby on Rails is a web application framework. Ruby predates Rails by about ten years. Don't confuse the two.
Ruby is not primarily a web programming language even though Ruby on Rails is certainly suited for web development. Ruby is a general purpose scripting language.
The FXRuby and WxRuby frameworks are the most fully featured GUI frameworks for Ruby. You can write the apps in Ruby and then generate a Windows executable. The frameworks are cross-platform, so you could also run the apps written in these on other platforms, like Linux or Mac OS X.
There are also a few other less popular approaches like QtRuby and Shoes, and you can even use IronRuby (a CLR Ruby implementation) to write a .Net application.
Ruby can be used for developing GUI applications, whether Windows specific or cross-platform.
For Windows targetted you should look at the work going on with IronRuby since they have good integration with the .NET framework overall and with Silverlight, in the event you want to do apps that can bridge web and desktop. At this point IronRuby can be used to develop for Windows Presentation Foundation (WPF) or WinForms.
For cross-platform you have Ruby bindings for QT, FOX and others.
I know this thread is old, but for future reference to anyone who's looking into options for using Ruby for a GUI app, don't use QtRuby. I had developed a project for school in about a week, fully functional and pretty, only to find out that I could not release it. There was simply no way to package and distribute the application without having your users simulate your exact environment (install all the gem dependencies, build Qt development libraries etc). I tried using:
- Crate: supposedly cross-platform, but I found only 1 usage example that's written in 2008 out of ~2 hours of googling, and the example basically covers a very specific subset of applications (some ssl/https authentication gem or w/e...)
- Ocra: this looks like a candidate, but it's windows-only and didn't meet my requirements, as I had to target the three primary platforms
- tar2rubyscript + rubyscript2exe: I had spent most of my time trying to get this to work because I've come across many who claimed that this is the way to go for distributing GUI apps built in ruby (albeit using other toolkits, Tk/GTK/wxRuby) but it didn't work either; I was endlessly faced with a cryptic error that basically breaks Qt::UiLoader functionality, in other words, you can't load .ui sheets you create with QtDesigner so...
Yes I'm angry and frustrated honestly, because I don't see the point of creating software that you just can't release for anyone to use. Now I'm left with a deadline coming up in a week, and I just hope I make it in time porting the app to C++.
So my answer is, don't use QtRuby. At least for now.