The defacto community scoreboard and event tracker

Probably the best free resource for learning Binary Exploitation & Reverse Engineering

A great resource of beginner focused challenges

A search engine for ctf writeups, indexed from CTFTime

List of wargame sites managed by Zardus

A online x86 assembler

Online decompiler that lets you compare results from Angr, Binary Ninja, Ghidra, and IDA

A web tool to apply different methods of encryption/decryption on input

An online interpreter, with over 680 different interpreters

Online Source viewer for Linux, glibc, and some other large oss repos

The best syscall table I've found, with architecture and version information

A nice website scraped from the Intel manual, much better than searching through the 5240 page pdf

Table breakdown of diffferent x86 opcodes

Python bytecode disassembler

Online lua bytecode decompiler

Includes a really nice debugger

Dynamic instrumentation toolkit

Powerful Multi-arch CPU emulator

The defacto python library for writing exploit scripts

GDB extension that provides significant UI improvements

Automates patching binaries to run with target libc

Determine libc version from symbol offsets

Dump seccomp rules from binaries

Identifies rop gadgets in binaries

Find libc one-gadgets and their constraints

Awesome intro to ARM and general exploitation techniques

Repo containing example heap exploits for many glibc versions

Large collection of exploit techniques shown through example CTF challenges

Good resource for some basic stack/heap techniques

Nice diagram from Pivoting around memory by Nick Gregory

Beginner crypto challenges

The platform for grinding crypto