What is LibGdx
LibGDX is a relatively low level, free, open source cross-platform game development framework. The goal of the project is to assist you in creating games/applications and deploy to the desktop and mobile platforms without getting in the way and letting you design however you like. It’s is written in Java programming language thus you need a Java development environment (JDK). IDE and build tools that support Java. To use LibGdx framework you must use Java programming language period.
LibGDX is free, licensed with Apache 2 open source software license, allowing everyone to use this project.
There are plenty of higher level tools in the framework to get you started quickly, and there is full access to low level API if and when you need to use them.
A place for comprehensive documentation on the LibGDX API and features.
Setup the Java development environment (Eclipse, IntelliJ IDEA, Android Studio, NetBeans)