GHIDRA is NSA’s home-grown classified software reverse engineering tool that agency experts have been using internally for over a decade to hunt down security bugs in software and applications. The tool is a Java-based reverse engineering framework that features a graphical user interface (GUI) and has been designed to run on a variety of platforms including Windows, macOS, and Linux. The NSA today publicly released the tool for free at the RSA conference, making it a great alternative to expensive commercial reverse engineering tools like IDA-Pro.
Source: https://thehackernews.com/2019/03/ghidra-reverse-engineering-tool.html