Boomerang

Boomerang is an open-source decompiler that translates supported machine-code binaries into C. It is best suited to developers and experimenters working with its specific native architectures and file formats. Its appeal is a BSD-licensed tool with command-line and GUI options; its output is not a recovery of the original source.

Overview

Boomerang turns supported binaries into C that can help with examining machine code. That output may differ from the original program's source, so it is an aid to analysis rather than a way to restore a project as written. The maker also warns that results on large binaries may disappoint, which makes it a weaker fit when dependable results across a large codebase matter.

The project is BSD licensed and free. It provides unit and regression tests, but building the regression suite on Windows is unsupported. Bug reports go through the GitHub issue tracker.

Key features

• Native-code decompilation: Boomerang outputs C from supported machine-code binaries. It does not handle bytecode, so it is unsuitable for bytecode-based targets.
• Focused architecture support: The supported architectures are x86 (IA-32 only), PPC, and ST20. This can suit a matching target, but excludes x86-64.
• Five input formats: It accepts ELF, PE, DOS MZ, DOS/4GW LE, and Mach-O. The defined set is useful for matching binaries, not a promise of support for other formats.
• CLI and GUI: The two interfaces offer a choice of workflow, without changing the architectures or formats the decompiler can handle.
• Source build: Building requires a 64-bit operating system and a C++17 compiler, along with CMake, Qt5, Capstone, GNU bison, and GNU flex. The 32-bit limitation and dependency list make setup a more natural fit for developers than casual users. Release versions have precompiled packages, while the project recommends building its development branch from source.

Pricing

Boomerang Decompiler costs nothing. The plan is open source and BSD licensed, with no paid tier described. That makes it a straightforward option when the supported targets fit; the trade-off is that a free license does not change its architecture coverage, lack of bytecode support, or warnings about output quality and large binaries.

Platforms

Build instructions cover Linux, macOS, and Windows. All require a 64-bit operating system and C++17; 32-bit systems are unsupported. Windows users should also note that the regression test suite cannot be built there.

Who it's for

Boomerang makes most sense for developers and experimenters who need to inspect a supported native binary, can work with its build requirements, and are comfortable treating generated C as an approximation. It is not a good fit for bytecode work, x86-64 targets, faithful source reconstruction, or large binaries where reliable results are essential.

Pros and cons

Pros

• Free and BSD licensed: The open-source license suits users who want a no-cost native-code decompiler.
• CLI and GUI options: Users can choose between command-line and graphical workflows.
• Linux, macOS, and Windows build guidance: The project documents builds across the three operating systems, subject to its 64-bit requirement.

Cons

• Narrow architecture and format coverage: It supports only x86 (IA-32), PPC, and ST20, and the five named input formats.
• No bytecode decompilation: It cannot serve bytecode-focused workflows.
• Approximate output and large-binary caveat: Generated C may differ from the original source, and the maker warns that large binaries may disappoint.
• Build prerequisites: A 64-bit system, C++17, and several dependencies make setup more involved than simply opening a ready-to-use application.

Alternatives

For a wider choice of decompilation tools, browse Decompiler Software or Reverse Engineering Tools.

• Binary Ninja is worth considering when its five-architecture free evaluation and education plan suits your needs; it does not include API or plugin access. Its Personal plan costs $199, paid once.
• IDA Pro may suit users who need its free x86-32 and x86-64 disassembly and two cloud-based decompilers, or who are considering a paid tier. IDA Pro Essential costs 1099.00 USD.
• JEB offers a free Community Edition for x86 and x86-64 decompilation, aimed at researchers, students, hobbyists, and nonprofit reverse engineers.
• rev.ng is an alternative whose decompilation pipeline is Free Software; its UI is planned for commercial cloud and standalone versions.
• Bytecode Viewer is a free, open-source GPL v3 option to consider when bytecode work is the priority.
• CFR is another free decompiler to consider.
• Ghidra is another free option.
• ILSpy is another free, MIT-licensed option.

Verdict

Boomerang is a sensible free choice for developers and experimenters whose native binaries match its architecture and format support, and who want C output with either a CLI or GUI. Its BSD license and zero price are clear advantages, but limited coverage, approximate output, and the warning about large binaries set firm boundaries. Look elsewhere for bytecode, x86-64 support, faithful source recovery, or more reliable work on large binaries.