Qt Quick Designer
On the other hand, Qt Quick Designer saves GUI files in both .ui.qml and .qml formats. Qt Quick is a very different type of GUI system in terms of technological concept and development approach, which we will cover in Chapter 14, Qt Quick and QML. Instead of XML format, Qt Quick Designer saves its data in a declarative language similar to JavaScript called QML. QML not only allows the designer to customize their GUI in a CSS-like (Cascading Style Sheets) fashion, it also allows the programmer to write functional JavaScript within the QML file. As we mentioned earlier, .ui.qml is the file format used for visual decoration only while .qml contains application logic.
If you're doing a simple program using Qt Quick, you don't have to touch any C++ coding at all. That's especially welcoming for web developers because they can immediately pick up Qt Quick and develop their own application without a steep learning curve; everything is just so familiar to them. For much more complex software, you can even link C++ functions from QML, and vice versa. Again, if you're interested in learning more about Qt Quick and QML, please head over to Chapter 14, QtQuick and QML.
Since Qt Creator is also written in Qt libraries itself, it is also totally cross-platform. Hence, you can use the same set of tools across different development environments and develop a unified workflow for your team, resulting in better efficiency and cost-effectiveness.
Other than that, Qt comes with many different modules and plugins, which cover a wide range of functionality you need for your projects. There is often no need for you to look for other external libraries or dependencies and try and implement them yourself. The abstraction layer of Qt makes the backend implementation invisible to the users and results in a unified coding style and syntax. If you try to put together a bunch of external dependencies yourself, what you'll find is each library has its own distinctive coding style. It's quite a mess when mixing up all the different coding styles in the same project, unless you make your own abstraction layer, which is a very time-consuming task. Since Qt already includes most, if not all the modules that you need to create feature-rich applications, there is no need for you to implement your own.
That being said, there are also many third libraries out there that extend Qt for features that Qt itself does not support, such as libraries that focus on game development or any other features that are designed for the specific user group.