netbeans.apache.org - My favorite Integrated Development Environment (IDE) is NetBeans because it has multiple language support (Java, PHP, Javascript, etc.) and is free / open-source.
https://www.anaconda.com/ - For doing data science, or working in STEM (Science, Technology, Engineering, Math) the Anaconda distribution is the easiest (and free) way to get started. In addition to the Python and R programming languages, it has a full suite of...