Open-source alternatives to Fernflower

de4dot is a .NET deobfuscator and unpacker designed to reverse obfuscation and restore readable code and metadata within .NET assemblies. It functions as a bytecode analyzer that simplifies control flow, strips anti-debugging protections, and extracts original payloads from packed executable wrappers. The project distinguishes itself through a modular deobfuscation pipeline and a sandbox environment used for dynamic string decryption, which executes decryption methods to replace encrypted strings with plain-text values. It can identify specific obfuscation tools through pattern-based binary a

Deobfuscator is a static analysis and manipulation framework designed to inspect and modify compiled Java class files and bytecode instructions. It functions as a deobfuscator that simplifies and reverses obfuscated Java applications, alongside operating as a security runtime environment that isolates and executes untrusted or potentially malicious Java bytecode safely. The project processes class files through a sequence of custom transformation passes using visitor-based instruction parsing and a static class analysis engine that maps out class hierarchies and cross-references without dynam

pycdc is a reverse engineering toolset that decompiles and disassembles compiled Python bytecode files back into readable source code. It parses .pyc file headers, reconstructs abstract syntax trees from bytecode instructions, and handles version-specific opcodes across Python versions 1.0 through 3.13 with endian-aware binary parsing. The tool recovers numeric constants, string literals, and marshalled Python objects from compiled bytecode, supporting both file-based and in-memory bytecode loading. It provides a human-readable disassembly listing of bytecode instructions alongside full sourc

gdsdecomp is a project recovery suite and game engine reverse engineering toolset. It functions as a bytecode decompiler, binary resource converter, and asset extraction tool designed to reconstruct original directory hierarchies and scripts from compiled binary game assets. The toolset specializes in GDScript bytecode decompilation and compilation, translating compiled bytecode back into human-readable source code or converting source code into executable bytecode for specific engine versions and commit hashes. It includes a game archive patcher to modify project archives by replacing intern

Reverse engineering and pentesting for Android applications

This project is a comprehensive Android reverse engineering suite that functions as a decompiler, bytecode deobfuscator, and malware analysis tool. It is designed to convert APK, DEX, and OAT binaries into human-readable source code using a native implementation that does not require a Java Virtual Machine. The platform is distinguished by its integration with Frida for dynamic analysis, allowing users to hook methods, inject custom JavaScript, and dump device memory in real time. It also features specialized security engines, including a taint propagation engine and a stack-state machine, to

Recaf is a suite of specialized tools for assembling, editing, deobfuscating, decompiling, and instrumenting Java bytecode and runtime processes. It provides a coordinated environment for modifying compiled Java class files and analyzing the behavior of Java applications. The project distinguishes itself through a multi-level abstraction layer that allows for editing across different formats and a pluggable framework that routes bytecode through multiple configurable decompilation engines. It includes an embedded scripting engine and plugin architecture to automate repetitive tasks and extend

Simplify is an Android virtual machine sandbox, bytecode execution tracer, and static analysis framework. It serves as a Dalvik bytecode deobfuscator designed to recover readable code from binaries by simulating program behavior without a physical device. The project distinguishes itself by using execution graph analysis to resolve reflection calls and simplify obfuscated code through constant propagation and dead code removal. It employs multi-path execution simulation to track all possible conditional branch outcomes and maps instruction flow to identify constant values. The system covers

ArchUnit is a Java architecture testing library and automated validator that analyzes compiled bytecode to verify that source code adheres to predefined design rules. It functions as a testing framework that fails builds when the actual code structure violates architectural constraints. The library uses a fluent rule specification to define constraints and employs bytecode analysis to inspect class relationships and package dependencies. This allows for the automated detection of circular dependencies and the enforcement of dependency rules between packages. The tool covers a range of struct

Steamless is a specialized utility designed to strip SteamStub digital rights management wrappers from game executables. It functions as a decryptor and unpacker that removes these protection layers to recover the raw binary data of the original application. By removing the platform-specific wrapper, the tool restores original entry points and enables executables to run without requiring an authenticated platform instance. This process prepares game binaries for modification by removing the layers that typically prevent third-party tools from accessing the code. The project utilizes static b

dex2jar is an Android dex decompiler and reverse engineering tool designed to convert Dalvik executable bytecode into Java class files. It functions as a bytecode converter that transforms compiled Android binaries into a format compatible with standard Java analysis tools. The project facilitates Android app decompilation and Java bytecode recovery by translating executable files into readable structures. This allows for the analysis of application logic and the identification of security vulnerabilities or malicious behavior during Android malware analysis. The tool performs static bytecod

Binaryen is a WebAssembly compiler toolchain and optimizer designed to transform, validate, and shrink binary modules. It provides a comprehensive intermediate representation framework that converts binary code into a single-assignment form to enable advanced program analysis and code transformation. The project includes a specialized transformation engine that applies iterative optimization passes to increase execution speed and reduce binary size. Additionally, it functions as a transpiler that translates WebAssembly binary modules into executable JavaScript for environments that lack nativ

dnSpy is a specialized toolset for the reverse engineering, analysis, and modification of compiled .NET binaries. It functions as a decompiler that converts assemblies back into readable high-level source code, an assembly editor for modifying bytecode and metadata, and a debugger for inspecting compiled binaries. The project integrates a hex editor specifically for inspecting and modifying raw bytes and Common Intermediate Language structures. It allows for the direct modification of binary contents to change application behavior without requiring the original project source files. The tool

python-uncompyle6 is a Python bytecode decompiler and reverse engineering tool designed to convert compiled bytecode files back into human-readable source code. It functions as a source code recoverer and bytecode disassembler, allowing for the analysis of internal program logic and the reconstruction of original language constructs. The tool provides cross-version support, enabling the analysis and recovery of source code from bytecode created across multiple different versions of the Python interpreter. This allows it to operate as a cross-version bytecode analyzer that can interpret varied

Luyten is an open source Java decompiler and bytecode analyzer designed to transform compiled class files back into high-level source code. It functions as a graphical user interface for the Procyon decompilation engine, allowing for the inspection and recovery of program logic from Java bytecode. The tool provides capabilities for Java reverse engineering and legacy code analysis, enabling the examination of third-party applications or libraries when original source code is unavailable. The system includes a desktop interface for browsing class hierarchies, recursive classpath scanning to

This project is a desktop application designed for the reverse engineering and inspection of compiled Java code. It functions as a graphical interface that translates Java bytecode back into readable source code, allowing users to examine the internal logic of class files and archives when original source files are unavailable. The tool provides a structured environment for navigating complex file hierarchies, including nested archives like JAR and WAR files. By maintaining an in-memory representation of loaded classes, it enables rapid searching and cross-referencing of code elements. The ap

Blackfriday is a Go library for parsing and converting Markdown text into HTML, LaTeX, and other structured formats. It functions as an extensible Markdown processor that transforms syntax into target markup languages. The project is distinguished by its pluggable rendering architecture, which allows for the production of diverse output targets such as Slack message styles, Confluence Wiki Markup, and GitHub Flavored Markdown. It supports custom syntax extensions including definition lists, footnotes, autolinks, and strikethroughs. The processor includes utilities for generating automatic ta

Resvg is a high-compliance SVG rendering library and parsing engine designed to convert scalable vector graphics into raster images. It functions as an SVG to raster converter that resolves XML trees and manages the transformation of vector data into bitmap formats. The project ensures cross-platform visual consistency by producing identical pixel-perfect output regardless of the operating system or CPU architecture. It distinguishes itself through a text layout engine that handles complex typography, including bidirectional reordering, vertical writing modes, and color emoji fonts. The libr

This is a TOML parser and serializer for the Go language. It serves as a data serialization library and configuration file mapper that encodes and decodes data between Go structures and the TOML configuration format. The library provides interfaces for custom type marshaling, allowing for specialized logic when parsing or serializing specific data types. It transforms structured objects into deterministic TOML documents for storage or transmission. The project covers a broad range of data processing capabilities, including structured value encoding, TOML data generation, and metadata inspect