App · Case study:
XY Remote: reconstructing XinYi amplifier BLE controlC2
XY Remote reconstructs BLE control for XinYi Sinilink amplifier boards in an iOS app and Swift library.
- App
- Protocol
Reviewed slopmaxxer/xy-remote@5ea829c
Curated reverse engineering resources
5,191Evidence class
- C0full software reconstruction
- C1partial scope or analysis entry
- C2code & docs, no demo or download
- C3notes only
- ?Source unavailable or unreadable at review time
Apps
370App · Case study:
RideLink: reconstructing TVS SmartXonnect scooter communicationC1
RideLink reconstructs TVS SmartXonnect scooter communication in an Android companion app.
- App
- Protocol
Reviewed aiyu-ayaan/RideLink@856edba
Protocol · Case study:
lumalou: reconstructing Fisher-Price Lumalou BLE controlC2
lumalou reconstructs local Bluetooth LE control of the Fisher-Price Lumalou bedtime device after its companion app was discontinued.
- Protocol
- App
Reviewed stramanu/lumalou@af0e3f3
App · Case study:
Scarlett MixControl: rebuilding control of first-generation Scarlett interfacesC1
Scarlett MixControl replaces Focusrite's MixControl 1.10.6 on modern macOS for first-generation Scarlett interfaces.
- App
- Protocol
App · Case study:
Mi Fitness Sync: reconstructing workout retrieval from the Android appC2
Mi Fitness Sync reconstructs workout retrieval from the Mi Fitness Android app and implements a Python CLI for activity export and Strava uploads.
- App
Reviewed kevinkwee/Mi-Fitness-Sync@b51fd42
Protocol · Case study:
SSL Console Control: reconstructing mixing-console UDP controlC2
SSL Console Control implements Python control of SSL Matrix-family and Sigma mixing consoles over their native UDP protocols.
- Protocol
- App
Reviewed koltyj/SSL@aacb2b0
App · Case study:
logitech-ipc-protocol: reconstructing Logi Options+ agent messagesC2
logitech-ipc-protocol reconstructs the Logi Options+ agent's local IPC messages for querying devices and changing their active host.
- App
- Protocol
App · Case study:
samsung-notes-format: decoding Samsung Notes handwritingC2
samsung-notes-format reconstructs the handwriting geometry stored in Samsung Notes .sdocx files.
- App
Reviewed bxff/samsung-notes-format@6f4b92a
App · Case study:
cam-server: reconstructing the Digicam Print Channel backendC3
cam-server implements a backend for the Digicam Print Channel, producing responses in the format the client expects and rendering images from its templates.
- App
- Protocol
Reviewed WiiLink24/cam-server@ab059bc
App · Case study:
bline: decoding LINE voice-call trafficC2
bline investigates an earlier LINE voice-call stack and supplies tools for its custom ZLIB-compressed SIP data.
- App
- Protocol
Reviewed thebabush/bline@0b70696
App · Case study:
WazeTripper: reconstructing Tripper Pod navigation over BLEC2
WazeTripper connects Waze navigation to a Royal Enfield Tripper Pod by patching a Waze Android APK and sending commands over a reconstructed BLE interface.
- App
- Protocol
Reviewed jnsdias/wazetripper@7c4235d
App · Case study:
device-reveng: rebuilding a Choiceway GT6-EAU head unit stackC1
device-reveng investigates a Choiceway GT6-EAU Android car head unit and rebuilds its launcher and operating-system layer.
- App
- Firmware
- Protocol
Reviewed armeehn/device-reveng@b5c07f6
Protocol · Case study:
VTech Baby Pro Bridge: reconstructing local camera streamingC2
VTech Baby Pro Bridge reconstructs local streaming from an RM-series camera through TUTK/Kalay and VTech's X25519 and ChaCha20-Poly1305 layer.
- Protocol
- App
App · Case study:
Reengineering Project for ibisPaint: investigating artwork and brush formatsC2
Reengineering Project for ibisPaint investigates the app's IPV artwork, IPCF configuration and IPBZ brush QR formats.
- App
Reviewed HatLink/reeng-ibispaint@39b8224
App · Case study:
caniOn Rebirth: reconstructing the Mitsubishi ZEV CAN client and protocolC2
caniOn Rebirth reconstructs the Mitsubishi ZEV CAN protocol used by the caniOn v152 Android app for the i-MiEV, iOn and C-Zero.
- App
- Protocol
Reviewed linuxkafe/caniOn-rebirth@abb8bb1
App · Case study:
AionLink Open: investigating ICCOA CarLink connectivity for the GAC AION i60C2
AionLink Open investigates ICCOA CarLink connectivity for the GAC AION i60 through static analysis of Android APKs and an independently written Android client.
- App
- Protocol
Reviewed codepdbh/aionlink-open@034635b
App · Case study:
claude-peer: reconstructing Claude's local peer IPCC2
claude-peer reconstructs the local Unix socket peer exchange used by Claude Code and Claude Desktop.
- App
- Protocol
Reviewed nsozturk/claude-peer@0ab59df
App · Case study:
Nona: reconstructing Redmi Note 10 Pro Max camera remosaic conditionsC1
Nona investigates the Redmi Note 10 Pro Max camera's 108 MP remosaic behavior and implements a Camera2 app around the observed ISO and AecLux conditions.
- App
Reviewed AbhiramJayasankar/redmi-note-10-pro-max-108mp-camera@d795d6b
App · Case study:
elevenlabs-reader-cli: reconstructing Reader app streamingC2
elevenlabs-reader-cli is a Python command-line client for creating ElevenLabs Reader documents and streaming their audio through the Reader WebSocket.
- App
- Protocol
Protocol · Case study:
Yi M1: reconstructing wireless camera control and live viewC2
Yi M1 wireless protocol research reconstructs the camera’s BLE pairing, Wi-Fi handoff, HTTP remote-control commands and UDP live-view frame format.
- Protocol
- App
Protocol · Case study:
TelloPython: reconstructing app-only Tello drone commandsC2
TelloPython implements Python control of Tello drone functions available through its mobile app beyond the documented API.
- Protocol
- App
Reviewed jaqxues/TelloPython@370497e
App · Case study:
Humax-CLI: reconstructing IR4000HD remote controlC2
Humax-CLI implements terminal control of the Humax IR4000HD receiver from findings the author attributes to reversing its Android app.
- App
- Protocol
Reviewed D4Vinci/Humax-CLI@838c6cc
App · Case study:
Swish QR format: mapping payment QR payloadsC2
Swish QR format documents QR-code payloads for Swish payments.
- App
Reviewed lindskogen/swish-qr-format@aa8ea0c
App · Case study:
baseus-desktop: reconstructing Baseus earbuds controlC1
baseus-desktop reconstructs Baseus earbuds control in a Windows and Linux desktop client.
- App
- Protocol
Reviewed elaxptr/baseus-desktop@ab2f1c4
App · Case study:
Samsung Cloud Notes: reconstructing cloud note accessC2
Samsung Cloud Notes reconstructs access to Samsung's private note-sync services in Mac, iOS, Android and command-line clients.
- App
- Protocol
App · Case study:
Music Tag Desktop: reconstructing an Android music tagger for WindowsC1
Music Tag Desktop reconstructs the behavior of Android Music Tag 1.2.5.2 as a Windows music-tag editor.
- App
Reviewed QingZhu233/music-tag-desktop@3435237
App · Case study:
vector-studio-re: reconstructing Vector Studio's automation protocolC2
vector-studio-re reconstructs the automation interface of Vector Studio 0.1.11 from its shipped Linux AppImage.
- App
- Protocol
App · Case study:
AirTray: reconstructing an Elgin Air cloud clientC1
AirTray reconstructs an Elgin Air app client as a Windows system-tray controller for compatible air conditioners.
- App
App · Case study:
HikVision QR export decoder: reconstructing Hik-Connect device exportsC2
HikVision QR export decoder reconstructs the format of Hik-Connect device export QR codes and provides a Python decoder and renewal command.
- App
Reviewed maxim-smirnov/hik-qr-export@65664fc
App · Case study:
ShatteredGlass: reconstructing SwiftUI Liquid Glass effectsC2
ShatteredGlass reconstructs SwiftUI's Liquid Glass appearance on macOS using a layered Core Animation view.
- App
Reviewed AlexStrNik/ShatteredGlass@0ce6e0d
App · Case study:
Grok3API: reconstructing Grok’s mobile gRPC clientC2
Grok3API implements a Python client for Grok’s mobile gRPC interface.
- App
- Protocol
Reviewed boykopovar/Grok3API@a63a58b
App · Case study:
Things Cloud Python client: reconstructing to-do requestsC2
The Things Cloud Python client reconstructs part of the service's request behavior from traffic produced by the Mac app.
- App
- Protocol
Reviewed disrupted/things-cloud-api@5698384
App · Case study:
NVFC: recovering undocumented NvAPI GPU controlsC2
NVFC implements undocumented NvAPI interfaces for NVIDIA GPU monitoring and configuration.
- App
Reviewed graphitemaster/NVFC@b9ca5cc
App · Case study:
SingStar Mic: reconstructing the microphone app protocolC2
SingStar Mic documentation reconstructs the Android and iOS app's local discovery, catalogue and game-service exchanges.
- App
- Protocol
Reviewed kevinvalk/re-singstar-mic@578384f
App · Case study:
Techstream for Linux: recovering Toyota diagnostic formats and workflowsC2
Techstream for Linux reconstructs selected Toyota and Lexus diagnostic resource formats, command behavior and transport handling in a Python GTK4 workbench.
- App
- Protocol
Reviewed gon7187/techstream@e2cec29
Protocol · Case study:
Fluval Plant Pro 4.0: reconstructing BLE light controlC2
The Fluval Plant Pro 4.0 project reconstructs the light's CBOR-over-BLE control protocol from the FluvalConnect Android app.
- Protocol
- App
App · Case study:
xtractedott: reconstructing the OTT compressor DSP coreC2
xtractedott reconstructs portions of Xfer Records' OTT VST multiband compressor in C.
- App
Reviewed jwfeniello/xtractedott@f3d3447
App · Case study:
OpenApe: reconstructing the Call of Duty 4 Asset ManagerC1
OpenApe reimplements the Call of Duty 4 mod tools' asset_manager.exe as a C++20 desktop editor.
Demo available · no screenshot - App
Reviewed Rex109/OpenApe@628cc12
App · Case study:
EOO: a Nintendo DS Wii-connection utility decompilationC2
EOO reconstructs the Nintendo DS Wii connection utility stored in Pokémon Diamond and Pearl.
- App
Reviewed PikalaxALT/eoo@b4057d1
App · Case study:
PictoChat: a matching DSi system-title decompilationC2
PictoChat's standalone DSi system title is being reconstructed as matching C source for its ARM components.
- App
- Binary
Protocol · Case study:
LibrePods: AirPods features on Android and Linux through a reverse-engineered protocolC1
Implements the proprietary protocol that AirPods use with Apple devices, which the author reports reverse-engineering, so that Android and Linux apps can switch noise-control modes, read ear detection and accurate battery levels, and use conversational awareness, head gestures and hearing-aid settings.
- Protocol
- App
Reviewed librepods-org/librepods@89356c0
Protocol · Case study:
OpenHaystack: tracking tags that use Apple Find MyC1
OpenHaystack uses a reconstructed Apple Find My protocol to build personal Bluetooth tracking tags and a Mac app that queries their location reports.
- Protocol
- App
Reviewed seemoo-lab/openhaystack@ea05dad
App · Case study:
PC-BASIC: a GW-BASIC-family interpreterC1
A cross-platform interpreter for GW-BASIC, BASICA, PCjr Cartridge BASIC, and Tandy 1000 GWBASIC.
- App
Reviewed robhagemans/pcbasic@6a3a035
App · Case study:
ReactOS: a Windows NT-compatible operating systemC2
Builds an open operating system intended to run applications and drivers written for the Windows NT family.
- App
- Binary
Reviewed reactos/reactos@fae4549
App · Case study:
viaduct: a Linux port of NetNewsWireC2
A Linux RSS reader in Rust and GTK4 that the README calls a port of NetNewsWire.
- App
Reviewed VirInvictus/Viaduct@a062290
App · Case study:
zalo-linux: a Linux package of the Zalo desktop appC2
Repackages VNG's Zalo desktop app for Linux from the official macOS installer.
- App
Reviewed thotam/zalo-linux@63b7293
App · Case study:
Free-BBN: recreating the PlayStation Broadband Navigator dashboardC2
Free-BBN recreates the PlayStation Broadband Navigator dashboard as a PS2 homebrew application built with ps2sdk and gsKit.
- App
Reviewed jegesmedve09/Free-BBN@26c9b49
App · Case study:
Serato Tags: reconstructing Serato DJ GEOB metadataC2
Serato Tags reconstructs the GEOB metadata structures that Serato DJ stores in audio files.
- App
Reviewed Holzhaus/serato-tags@26cbdf2
App · Case study:
lsdj-decomp: matching Little Sound Dj 9.4.2 reconstructionC2
lsdj-decomp reconstructs Little Sound Dj 9.4.2 using tracked symbol maps, ROM analysis tools and C translations substituted into locally generated RGBDS assembly.
- App
Reviewed tetrisgm/lsdj-decomp@49b55fa
App · Case study:
Moonlight Windows: reconstructing NVIDIA GameStream for WindowsC2
Moonlight Windows recreates NVIDIA Shield GameStream access on Windows and Windows Phone 8.1 after reverse engineering the Shield streaming software.
- App
- Protocol
App · Case study:
sas7bdat: reconstructing the SAS7BDAT database formatC2
sas7bdat reconstructs the binary layout of SAS7BDAT database files by examining sample databases for interoperability with R.
- App
Reviewed BioStatMatt/sas7bdat@d6f8942
App · Case study:
Outlook drag and drop: decoding RenPrivateMessages clipboard dataC2
The Outlook drag-and-drop investigation decodes the RenPrivateMessages OLE clipboard stream to recover identifiers of the original Outlook message.
- App
- Protocol
App · Case study:
hbkit: reconstructing Synology Hyper Backup archivesC1
hbkit reconstructs the Synology Hyper Backup .hbk archive format and implements a Python file-recovery tool.
- App
Reviewed YordiLorenzo/hbkit@db587c8
App · Case study:
Murmelbahn: decoding GraviTrax course filesC2
Murmelbahn decodes GraviTrax course data obtained through the Ravensburger app API and presents course details and bills of materials in a web app.
- App
Reviewed lfrancke/murmelbahn@8d7974a
App · Case study:
LSDisJ: disassembling Little Sound DJC2
LSDisJ disassembles Little Sound DJ Game Boy ROM versions 9.2.L and 8.5.1 from user-provided copies.
- App
Reviewed rbong/LSDisJ@7db8faa
App · Case study:
HoMM3 Horn of the Abyss: reconstructing map-editor classesC3
The h3maped project reconstructs C++ classes from the HoMM3 Horn of the Abyss map editor's executable.
- App
Reviewed crackedmind/h3maped-decomp@b06b66f
App · Case study:
Wii Motion Plus Demo Video Player: Wii decompilationC2
Wii Motion Plus Demo Video Player reconstructs a Wii video-player program found in several games.
- App
Reviewed RootCubed/mpls_movie-decomp@c935a5d
App · Case study:
Cordial: hosting the Roblox Android client on LinuxC1
Cordial hosts the unmodified Roblox Android client on Linux through a ported bionic linker, ELF import resolution and substitutes for Android JNI and framework calls.
- App
Reviewed luohoa97/cordial@378c83b
App · Case study:
Little Sound Dj: matching Game Boy disassembly and C recoveryC2
The LSDj project reconstructs Little Sound Dj 9.4.0 with symbol maps, matching C functions and an RGBDS assembly tree generated from the user's ROM.
- App
Reviewed gmoben/lsdj-decompiled@96bdca6
App · Case study:
VitalWear: recreating Vital Bracelet BE on Wear OSC2
VitalWear recreates Bandai Vital Bracelet BE gameplay as a Wear OS watch app with a phone companion.
- App
Reviewed cfogrady/VitalWear@bb148e1
App · Case study:
Moonglow Toolset: rebuilding the Aurora module editorC1
Moonglow Toolset reimplements the Aurora module editor for Neverwinter Nights: Enhanced Edition in Rust, egui and wgpu.
- App
Reviewed jadzziaa/moonglow-toolset@98e2bc6
App · Case study:
cpr2rpp: reconstructing the Cubase 12 project formatC2
cpr2rpp documents the empirically recovered Cubase 12 CPR project format and converts selected project data into REAPER RPP files.
- App
Reviewed daniel-lynch/cpr2rpp@7b75279
App · Case study:
wii-news-channel: a matching Wii News Channel decompilationC2
wii-news-channel reconstructs the USA v7 Wii News Channel as C/C++ source intended to build a byte-identical main.dol.
- App
App · Case study:
TraktorMappingFileFormat: Traktor Pro controller-mapping formatC2
TraktorMappingFileFormat documents the controller-mapping data stored in Traktor Pro 2.x TSI files.
- App
App · Case study:
AvatarEditorRecomp: a Kinect-preview Avatar Editor PC portC1
AvatarEditorRecomp statically recompiles the Fall 2010 Kinect-preview Xbox 360 Avatar Editor into a PC application with ReXGlue.
- App
App · Case study:
perception-pnrf: PNRF measurement format reconstructionC1
perception-pnrf documents the reverse-engineered PNRF measurement file format used by HBK Perception and provides Python and C# parsers.
Demo available · no screenshot - App
Reviewed codeberg.org/Apollo3zehn/perception-pnrf/src/commi…
App · Case study:
metars_cgi: reconstructing the NCAR Java METAR viewer serverC2
metars_cgi reconstructs the data server used by NCAR's Java METAR viewer.
- App
Reviewed codeberg.org/PurpleJillybeans/metars_cgi/src/commi…
App · Case study:
Xbox Demos Decompilation: a functional reconstruction of the Xbox demo launcherC2
Xbox Demos Decompilation reconstructs the Xbox application that launches videos and demos from the North American BLiNX: The Time Sweeper disc.
- App
Reviewed codeberg.org/KeybadeBlox/XDemos-Decomp/src/commit/…
App · Case study:
ag-psd: reconstructing PSD document reading and writingC1
ag-psd reconstructs reading and writing of Photoshop PSD documents in JavaScript and TypeScript using format references and trial and error.
- App
Reviewed Agamnentzar/ag-psd@a74425d
App · Case study:
locus-poi-db: LoMaps POI database formatC3
locus-poi-db investigates the POI database format used with LocusMaps LoMaps.
- App
Reviewed noschinl/locus-poi-db@6a5e517
App · Integration:
JADX-AI-MCPC1
JADX plugin paired with a Python MCP server to inspect decompiled Android classes, resources, cross-references and debugger context.
- App
Reviewed zinja-coder/jadx-ai-mcp@ce64f22
App · Integration:
apktool-mcp-serverC1
Python MCP server that drives a local Apktool install so agents can decode APKs; list, read, search and edit smali and resource files; read AndroidManifest.xml and apktool.yml; and rebuild the project.
- App
App · Integration:
frida-mcp (yfe404)C2
Frida MCP server with persistent instrumentation sessions, runtime inspection and Android static-to-dynamic navigation.
- App
- Game
Reviewed yfe404/frida-mcp@fb7d6c7
App · Integration:
Super TrouperC1
Single-binary Frida MCP server for discovering devices, managing process sessions and loading instrumentation scripts.
- App
- Game
Reviewed crissyfield/super-trouper@b3d31ad
Native binaries
502Binary · Tool:
GhidraC1
Open-source analysis suite for disassembly, decompilation, graphs and Java/Python automation across executable formats.
- Binary
- Game
- Firmware
Binary · Tool:
radare2C1
Scriptable command-line framework for inspecting, disassembling, debugging and modifying binaries across many architectures.
- Binary
- Game
Reviewed radareorg/radare2@6ac96f5
Binary · Tool:
CutterC1
Rizin-powered graphical reverse-engineering workspace with extensible views and Ghidra decompiler integration.
- Binary
- Game
Reviewed rizinorg/cutter@734acd1
Binary · Tool:
QilingC2
Python emulation framework that adds OS, filesystem and API behavior around CPU emulation for instrumented binary analysis.
- Binary
- Firmware
Reviewed qilingframework/qiling@206b90f
Binary · Tool:
Unicorn EngineC2
Multi-architecture CPU emulator for executing selected instruction ranges with register, memory and hook control.
- Binary
- Game
- Firmware
Reviewed unicorn-engine/unicorn@c24c9eb
Binary · Tool:
angrC2
Python binary-analysis framework combining control-flow recovery, symbolic execution, data-flow analysis and decompilation.
- Binary
Reviewed angr/angr@ae9f578
Binary · Tool:
LIEFC1
Library for structured parsing and modification of executable formats including ELF, PE and Mach-O.
- Binary
Reviewed lief-project/LIEF@b68429c
Binary · Tool:
CapstoneC2
Disassembly library with architecture-neutral APIs and instruction details for custom binary-analysis pipelines.
- Binary
Reviewed capstone-engine/capstone@d7ef910
Binary · Tool:
ImHexC1
Hex editor with a binary-pattern language, structured data inspection and visual tools for understanding file formats.
- Binary
- Game
- Firmware
Reviewed WerWolv/ImHex@fddad83
Binary · Tool:
x64dbgC1
Windows binary debugger with disassembly, memory views and plugins for analyzing programs without source code.
- Binary
Reviewed x64dbg/x64dbg@ac4db12
Binary · Tool:
GDBC3
Native and remote debugger for controlling execution and inspecting live or crashed program state.
- Binary
Reviewed sourceware.org/gdb
Binary · Tool:
rrC2
Records process execution and replays it under GDB, enabling repeatable inspection and reverse execution.
- Binary
Reviewed rr-debugger/rr@7ff9786
Binary · Tool:
DiaphoraC1
IDA-based binary diffing that matches functions and transfers names, comments and types between analyzed versions.
- Binary
- Game
Reviewed joxeankoret/diaphora@a7e1594
Binary · Tool:
BinDiffC2
Compares disassembled binaries to find matching functions and changed code across versions.
- Binary
- Game
Reviewed google/bindiff@882333b
Binary · Tool:
Detect It EasyC1
Format-aware file identification and static inspection using parsers, signatures and programmable heuristics.
- Binary
- Game
Reviewed horsicq/Detect-It-Easy@bd693a6
App · Tool:
r2fridaC1
Use radare2 commands and Frida instrumentation together to inspect local or remote process memory, symbols, classes, and runtime calls on desktop and mobile targets.
- App
- Binary
Reviewed nowsecure/r2frida@4f1f8d7
Binary · Tool:
Kaitai StructC2
Turn documented binary layouts into reusable parsers for files and network packets.
- Binary
- Firmware
- Protocol
Reviewed kaitai-io/kaitai_struct@5ca6630
Binary · Tool:
GoReSymC2
Recover Go build metadata, function names and address ranges, source file and line tables, embedded types and strings from Go binaries, including stripped and some malformed unpacked samples.
- Binary
Reviewed mandiant/GoReSym@722897e
Binary · Tool:
rev.ngC2
Open-source decompilation pipeline that lifts x86-64, AArch64, i386, ARM and MIPS code with QEMU, runs LLVM-based analyses and emits C designed to be valid and recompilable.
- Binary
Reviewed revng/revng@57d81a3
Binary · Tool:
RizinC2
Command-line reverse-engineering framework that began as a fork of radare2.
- Binary
- Game
Reviewed rizinorg/rizin@db112e5
Binary · Tool:
Decompiler ExplorerC2
Web service at dogbolt.org that runs one small uploaded executable through many decompilers and shows their C-like output side by side, described as Compiler Explorer in reverse.
- Binary
Binary · Tool:
pwndbgC1
Python plug-in that loads into GDB, or runs as a REPL around LLDB, to make live program state easier to inspect.
- Binary
Reviewed pwndbg/pwndbg@3044ccd
Binary · Tool:
DynamoRIOC2
Runtime code manipulation system for building dynamic tools that observe or transform any part of an unmodified program while it runs.
- Binary
Reviewed DynamoRIO/dynamorio@6d2165a
Binary · Tool:
Decompyle++ (pycdc)C2
C++ disassembler and decompiler for compiled Python bytecode that aims to support bytecode from any Python version.
- Binary
- App
Reviewed zrax/pycdc@b428976
Binary · Tool:
cwe_checkerC2
Static analyzer from Fraunhofer FKIE that searches binary executables, mainly Linux and Unix ELF files, for code paths matching Common Weakness Enumeration bug classes such as buffer overflows, use-after-free and double free, NULL pointer dereferences, format strings and integer overflows.
- Binary
- Firmware
Reviewed fkie-cad/cwe_checker@7288311
Binary · Tool:
FLARE-VMC1
Mandiant FLARE installer that sets up and maintains a Windows virtual machine for reverse engineering and malware analysis.
- Binary
Reviewed mandiant/flare-vm@5dc321d