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

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

Repo containing example heap exploits for many glibc versions

Determine libc version from symbol offsets