How to write a cross-platform program?

Question

Greetings,

I want to write a small cross-platform utility program with GUI in it. What language/GUI-library should I stick to? Is it possible whatsoever?

Thi

Answer 1

Try RealBasic. Visual Basic-like syntax, targets Win32, OS X and Linux. I don't know any details about targetting Linux, but for any cross-platform development I've done between Win32 and OS X its been a dream.

http://www.realbasic.com

Edit: Generates native executables. There is a small cost - $100.

Answer 2

You want to develop a cross-platform program natively? Uh...I don't think that'll work, mainly because that phrase is a paradox. If you write native code, it by its very nature will only run on the platform you programmed it for. ;-) That's what the Frameworks are all about.

So what you should do instead is use a very slim framework if your program is going to be so small. itsmatt's idea of Qt is a possibility.

Answer 3

How about Python using Qt or Wx and then using PythonToExe to make a 'distributable'

Thought will have to giving to the development to ensure that no native functionality is used (i.e. registry etc.) Also things like line breaks in text files will have different escape characters so will need to be handled

Answer 4

I agree with David Wees and Georgi,

Java is cross-platformness par excellence. You literally write once and run everywhere. With no need of compiling your code for each target OS or bitness, no worries about linking against anything, etc.

Only thing is, as you pointed out, that a JRE must be installed, but it's quick and straightforward to do even for novice end-users (it's a matter of clicking "Next>" a few times in the installer).

And with Java Web Start deployment gets even easier: the user just clicks the launch button on a webpage and the application runs (if the proper JVM is installed according to what specified in the JNLP descriptor) or the user gets redirected to the Java download page (if no suitable JVM is found).

Answer 5

The problem is: If you do not want to have a GUI but you do not want to ask the user to download an eternal API, Framework or virtual machine to run it in, be it TCL/TK, Java or QT etc. then you get lost pretty fast.

The reason is: You would have to rebuild all the (GUI) functionality those APIs, frameworks and virtual machines provide you with to be platform independent. And that's a whole lot of work to do... .

On the other side: The Java virtual machine is installed on nearly any operating system from scratch, why not give this one a shot?

Answer 6

Which OS's do you have in mind when you say cross-platform?

As Epaga correctly points out, native and cross-platform are mutually exclusive. You can either write multiple versions that run natively on multiple platforms, or you need to use some cross-platform framework.

In the case of the cross-platform framework approach, there will always be extra installs required. For example, many here suggest using Python and one of its frameworks. This would necessitate instructing people to install python - and potentially the framework - first.

If you are aiming at Windows and OS X (and are prepared to experiment with alpha-release code for Linux if support for that OS is required), I'd highly recommend you take a look at using Adobe AIR for cross-platform GUI applications.