First, go to http://qt.io and click on Download. This should bring you to a page containing a list of options for different licensing schemes. To use the open source version, choose the Open Source edition licensed under GPL and LGPL. Then, you can click on the Download Now button to retrieve the online installer for the platform that you are currently running on or you can click on any of the header sections to reach a more comprehensive list of options. The links to online installers are at the beginning of the list, as shown in the following screenshot. Click and download the one suited to your host machine:

When the download completes, run the installer, as shown:

Click on Next and after a while of waiting as the downloader checks remote repositories, you'll be asked for the installation path. Be sure to choose a path where you have write access (it's best to put Qt into your personal directory unless you ran...

After Qt Creator starts, you should be presented with the following screen:

The program should already be configured properly for you to use the version of Qt and compiler that were just installed, but let's verify that anyway. From the Tools menu, choose Options. Once a dialog box pops up, choose Build & Run from the side list. This is the place where we can configure the way Qt Creator builds our project. A complete build configuration is called a kit. It consists of a Qt installation and a compiler that will be executed to perform the build. You can see tabs for all the three entities in the Build & Run section of the Options dialog box.

Let's start with the Compilers tab. If your compiler was not autodetected properly and is not in the list, click on the Add button, choose your compiler type from the list, and fill the name and path to the compiler. If the settings were entered correctly, Creator will autofill all the other details. Then, you can...

Qt comes with a lot of examples. Let's try building one to check whether the installation and configuration were done correctly. In Qt Creator, click on the Welcome button on the top-left corner of the window to go the initial screen of the IDE. On the right-hand side of the page that appears (refer to the previous screenshot) there are a couple of tabs among which one of them happens to be called Examples. Clicking on that tab will open a list of examples with a search box. Make sure that the version of Qt you just installed is chosen in the list next to the search box. In the box, enter aff to filter the list of examples and click on Affine Transformations to open the project. If you are asked whether you want to copy the project to a new folder, agree. Qt Creator will then present you with the following window:

Let's try building and running the project to check whether the building environment is configured properly. First, click on the icon in the action bar directly over the green triangle icon to open the build configuration popup, as shown in the following screenshot:

The exact content that you get may vary depending on your installation, but in general, on the left-hand side you will see the list of kits configured for the project and on the right-hand side you will see the list of build configurations defined for that kit. Choose a kit for your desktop installation and any of the configurations defined for that kit. You can adjust configurations by switching Qt Creator to the project management mode by clicking on the Projects button in the working mode selector bar. There, you can add and remove kits from the project and manage build configurations for each of the kits, as shown in the following screenshot:

You can...

In most cases for desktop and mobile platforms, the binary release of Qt you download from the webpage is sufficient for all your needs. However, for embedded systems, especially for those ARM-based systems, there is no binary release available or it is too heavy resource-wise for such a lightweight system. In such cases, a custom Qt build needs to be performed. There are two ways to do such a build. One is to download the sources as a compressed archive just like the binary package. The other is to download the code directly from a Git repository. Since the first way is pretty much self-explanatory, we'll focus on the second approach.

First, you need to install Git on your system if you don't already have it. How to do that depends on your operating system. For Windows, simply download an installer from https://git-for-windows.github.io. For Mac, the installer is available at http://code.google.com/p/git-osx-installer. For Linux, the simplest way is to use your system's package manager. For instance, on Debian-based distributions, just issue the sudo apt-get install git command on a terminal and wait until the installation gets completed.

Afterwards, you need to clone Qt's Git repository. Since Git is a command-line tool, we'll be using the command line from now on. To clone Qt's repository to a directory where you want to keep the sources, issue the following command:

git clone git://code.qt.io/qt/qt5.git

If all goes well, Git will download a lot of source code from the network and create a qt5 directory, containing all the files that were...