* [Interactive Disassembler (IDA Pro)](https://www.hex-rays.com/products/ida/) - Proprietary multi-processor disassembler and debugger for Windows, GNU/Linux, or macOS; also has a free version, [IDA Free](https://www.hex-rays.com/products/ida/support/download_freeware.shtml).
* [WDK/WinDbg](https://msdn.microsoft.com/en-us/windows/hardware/hh852365.aspx) - Windows Driver Kit and WinDbg.
* [OllyDbg](http://www.ollydbg.de/) - x86 debugger for Windows binaries that emphasizes binary code analysis.
* [Radare2](http://rada.re/r/index.html) - Open source, crossplatform reverse engineering framework.
* [x64dbg](http://x64dbg.com/) - Open source x64/x32 debugger for windows.
* [Immunity Debugger](http://debugger.immunityinc.com/) - Powerful way to write exploits and analyze malware.
* [Evan's Debugger](http://www.codef00.com/projects#debugger) - OllyDbg-like debugger for GNU/Linux.
* [Medusa](https://github.com/wisk/medusa) - Open source, cross-platform interactive disassembler.
* [plasma](https://github.com/joelpx/plasma) - Interactive disassembler for x86/ARM/MIPS. Generates indented pseudo-code with colored syntax code.
* [peda](https://github.com/longld/peda) - Python Exploit Development Assistance for GDB.
* [dnSpy](https://github.com/0xd4d/dnSpy) - Tool to reverse engineer .NET assemblies.
* [binwalk](https://github.com/devttys0/binwalk) - Fast, easy to use tool for analyzing, reverse engineering, and extracting firmware images.
* [PyREBox](https://github.com/Cisco-Talos/pyrebox) - Python scriptable Reverse Engineering sandbox by Cisco-Talos.
* [Voltron](https://github.com/snare/voltron) - Extensible debugger UI toolkit written in Python.
* [rVMI](https://github.com/fireeye/rVMI) - Debugger on steroids; inspect userspace processes, kernel drivers, and preboot environments in a single tool.
* [Frida](https://www.frida.re/) - Dynamic instrumentation toolkit for developers, reverse-engineers, and security researchers.
- https://microcorruption.com/ - Given a debugger and a device, find an input that unlocks it. Solve the level with that input.
- http://reversing.kr/challenge.php - This site tests your ability to Cracking & Reverse Code Engineering.
- https://www.malwaretech.com/beginner-malware-reversing-challenges - The purpose of these challenges is to familiarize beginners with common malware techniques.
- https://crackmes.one/ - This is a simple place where you can download crackmes to improve your reverse engineering skills.
- https://challenges.re/ - Well, "challenges" is a loud word, these are rather just exercises for RE.
- https://reverse.put.as/crackmes/ - A collection of crackmes for OS X. Send them to me if you have new ones to add!
- https://join.eset.com/en/challenges - If you want to join the team that every day faces global cyber-threats, uncover a hidden puzzle in the crackme program and prove us your potential.
- http://flare-on.com/ - FireEye's challenge RE.
- https://ropemporium.com/ - Learn return-oriented programming through a series of challenges designed to teach ROP techniques in isolation, with minimal reverse-engineering and bug-hunting.