Pros of Unicorn

• Unicorn is a well-established and widely-used CPU emulator, supporting a wide range of architectures including ARM, MIPS, and x86.
• The project has a large and active community, with regular updates and a wealth of documentation and resources available.
• Unicorn provides a comprehensive API for interacting with the emulator, making it a powerful tool for a variety of use cases.

Cons of Unicorn

• Unicorn is primarily written in C, which may not be the most accessible language for some developers.
• The project's focus on low-level emulation may make it less suitable for certain high-level use cases, where a higher-level abstraction might be more appropriate.
• Unicorn's licensing (GPL v2) may be a concern for some users who require more permissive licensing terms.

Code Comparison

Unicorn:

uc_engine *uc;
uc_err err = uc_open(UC_ARCH_X86, UC_MODE_32, &uc);
if (err != UC_ERR_OK) {
    printf("Failed on uc_open() with error: %u\n", err);
    return;
}

uc_mem_map(uc, 0x1000, 0x4000, UC_PROT_ALL);
uc_mem_write(uc, 0x1000, code, sizeof(code));

uc_hook_add(uc, &hook, UC_HOOK_CODE, hook_code, NULL, 1, 0);

uc_emu_start(uc, 0x1000, 0x1010, 0, 0);

Iced:

let mut cpu = Cpu::new(CpuMode::Long64);
cpu.set_instruction_pointer(0x1000);
cpu.write_memory(0x1000, &code);

let mut handler = InstructionHandler::new(&mut cpu);
handler.hook_code(0x1000, 0x1010, |cpu, _addr, _len| {
    // Handle instruction
    Ok(())
});

cpu.run();

Pros of Capstone

• Multi-architecture support: Covers a wide range of CPU architectures
• Mature and well-established: Used in many production environments
• Extensive language bindings: Supports various programming languages

Cons of Capstone

• Performance: Generally slower than Iced for x86/x64 disassembly
• Memory usage: Typically consumes more memory than Iced
• Less focus on x86/x64: Not as specialized for these architectures

Code Comparison

Iced (Rust):

use iced_x86::{Decoder, Formatter, Instruction, IntelFormatter};

let bytes = b"\x48\x8B\x05\x39\x00\x00\x00";
let mut decoder = Decoder::new(64, bytes, 0);
let mut instruction = Instruction::default();
while decoder.can_decode() {
    decoder.decode_out(&mut instruction);
    // Process instruction
}

Capstone (C):

#include <capstone/capstone.h>

csh handle;
cs_insn *insn;
size_t count;
if (cs_open(CS_ARCH_X86, CS_MODE_64, &handle) == CS_ERR_OK) {
    count = cs_disasm(handle, code, code_size, address, 0, &insn);
    // Process instructions
    cs_free(insn, count);
    cs_close(&handle);
}

Both libraries provide disassembly capabilities, but Iced is more focused on x86/x64 performance, while Capstone offers broader architecture support.

Pros of asmjit

• Supports multiple architectures (x86, x64, ARM, AArch64)
• More comprehensive JIT compilation capabilities
• Actively maintained with frequent updates

Cons of asmjit

• Steeper learning curve due to more complex API
• Larger codebase, potentially leading to longer compilation times
• Less focused on disassembly compared to iced

Code Comparison

iced (Rust):

use iced_x86::{Decoder, Formatter, Instruction, NasmFormatter};

let bytes = b"\x48\x89\x5C\x24\x10\x48\x89\x74\x24\x18\x55\x57\x41\x56\x48\x8D\x6C\x24\xC0";
let mut decoder = Decoder::with_ip(64, bytes, 0x1000, 0);
let mut instruction = Instruction::default();

asmjit (C++):

#include <asmjit/asmjit.h>
using namespace asmjit;

JitRuntime rt;
CodeHolder code;
code.init(rt.environment());
x86::Assembler a(&code);

a.mov(x86::rax, x86::rcx);

Both libraries offer powerful assembly manipulation capabilities, but they cater to different use cases. iced excels in disassembly and analysis, while asmjit provides more comprehensive JIT compilation features across multiple architectures. The choice between them depends on the specific requirements of your project and your preferred programming language.

Pros of Keystone

• Multi-architecture support (ARM, MIPS, PowerPC, Sparc, SystemZ, XCore, x86)
• Bindings for multiple programming languages (Python, Ruby, Go, etc.)
• Extensive documentation and examples

Cons of Keystone

• Less frequent updates and maintenance
• Larger codebase, potentially more complex to contribute to
• Slower assembly process for large amounts of code

Code Comparison

Keystone (Python):

from keystone import *

ks = Ks(KS_ARCH_X86, KS_MODE_32)
encoding, count = ks.asm("mov eax, 1")

Iced (Rust):

use iced_x86::{Assembler, Code, Register};

let mut asm = Assembler::new(32).unwrap();
asm.mov(Register::EAX, 1).unwrap();
let bytes = asm.assemble(0x1000).unwrap();

Both libraries provide assembler functionality, but Iced focuses specifically on x86/x64 architectures, while Keystone supports multiple architectures. Iced is written in Rust, offering memory safety and performance benefits, whereas Keystone is primarily written in C with bindings for various languages.

Pros of Zydis

• Zydis is a lightweight and fast x86/x86-64 disassembler library, which can be useful for a variety of applications such as malware analysis, reverse engineering, and debugging.
• Zydis has a well-documented API and provides a range of features, including instruction decoding, operand extraction, and instruction information retrieval.
• Zydis is actively maintained and has a large community of contributors, ensuring regular updates and improvements.

Cons of Zydis

• Zydis is primarily focused on x86/x86-64 architectures, while Iced supports a wider range of architectures, including ARM, RISC-V, and PowerPC.
• The documentation for Zydis may not be as comprehensive as Iced, which has a more extensive set of examples and tutorials.
• Zydis may have a steeper learning curve for developers who are not familiar with the x86/x86-64 architecture.

Code Comparison

Iced:

var decoder = Decoder.Create(64);
var code = new byte[] { 0x48, 0x89, 0x44, 0x24, 0x08 };
var instruction = decoder.Decode(code, 0);
Console.WriteLine(instruction.Mnemonic); // mov

Zydis:

zydis_decoder_t decoder;
zydis_decoder_init(&decoder, ZYDIS_MACHINE_MODE_LONG_64, ZYDIS_ADDRESS_WIDTH_64);
zydis_decoded_instruction_t instruction;
zydis_status_t status = zydis_decoder_decode_buffer(&decoder, (void*)"H\x89D$\x08", 5, &instruction);
printf("%s\n", instruction.mnemonic.str); // mov