Disassemblers, Decompilers, Development Tools, Schematic/PCB Capture and other reverse engineering software. If you used it while reverse engineering, list it here!
Universal Radio Hacker - tool to analyze and extract data from SDR-captured radio signals (especially pilots, ISM RF devices, etc). See youtube for tutorials and examples.
Binary reverse engineering
Binary Ninja - reverse-engineering platform that can disassemble a binary and display the disassembly in linear or graph views.
IDA - The IDA Disassembler and Debugger is an interactive, programmable, extensible, multi-processor disassembler hosted on Windows, Linux, or Mac OS X.
Vivisect - Vivisect binary analysis framework. Includes Disassembler, Debugger, Emulation and Symbolik analysis engines. Includes built-in Server and Shared-Workspace functionality. Runs interactive or headless, programmable, extensible, multi-processor disassembler hosted on Windows, Linux, or Mac OS X (Pure-Python, using ctypes to access underlying OS debug mechanism). Supports RevSync via plugin, allowing basic collaboration with Binja, Ghidra, and IDA. Criticisms (from a core dev): "Graph View could use some work, slower than Binja and IDA (due to Python), documentation like an OpenSource Project... but we keep working to make it better. PR's and suggestions welcome." Best installed via Pip:
python3 -m pip install vivisect
Veles - Open source tool for binary data analysis (No longer actively developed).
Tools are great, and sometimes free! Without knowing how to use them, they can be a big waste of time. Better to spend your time learning the basics, then apply your knowledge.
Reverse Engineering Tutorial - A comprehensive reverse engineering tutorial covering x86, x64, 32-bit ARM & 64-bit ARM architectures.