x64dbg Debugger

This open-source x64 and x32 debugger for Windows provides a comprehensive reverse engineering and malware analysis toolset comparable to commercial debuggers like OllyDbg and Immunity Debugger. Originally created by Duncan Ogilvie (mrexodia) in 2013, the project has over 41,000 stars as of 2026 and is the most popular open-source debugger for Windows binary analysis. Key features include: x64 and x32 support (separate binaries for 64-bit and 32-bit debugging with identical interfaces), debugging engine (intellibreakpoint, conditional breakpoints with expressions, hardware breakpoints for data and code, memory breakpoints, and message breakpoints), disassembly view (x86-64 instruction disassembly with Intel and AT&T syntax, cross-references, jump arrows, and inline analysis), memory map (listing all memory regions with base address, size, protection flags, and info), register view (general-purpose, segment, flag, FPU, MMX, SSE, AVX, and debug registers with modification and pin-to-register), stack view (call stack reconstruction with return addresses, arguments, and local variables), references view (search results for strings, constants, intermodular calls, and pattern matches), executable modules (listing all loaded DLLs with base, size, entry point, and path), handles and threads (enumerating process handles, thread contexts, and window objects), command system (over 200 scripting commands for automation and custom analysis), expression evaluator (C-like expression syntax with registers, memory access, mathematical operations, and label resolution), plugin SDK (C-based plugin API enabling third-party extensions including Scylla for IAT rebuilding, xAnalyzer, and YARA integration), and trace recording (recording executed instructions for coverage analysis and taint tracking).