UltraJSON is a high-performance JSON encoder/decoder library for Python, implemented entirely in C with Python bindings. It provides drop-in replacements for Python's standard json module (ujson.dumps, ujson.loads, ujson.dump, ujson.load) and offers configuration options for ASCII encoding, HTML character escaping, forward slash escaping, indentation, sorting keys, NaN/Infinity handling, and customizable separators. The library's core architecture consists of a hand-optimized C state machine for decoding and a recursive encoder that handles Python objects via a type-context system. It bundles a copy of the double-conversion library for precise floating-point serialization and uses a stack-first, heap-later buffer allocation strategy. Despite being in maintenance-only mode due to architectural security concerns, the codebase exhibits strong craftsmanship: meticulous memory management, comprehensive UTF-8 validation, support for surrogate pairs, fuzz testing with ref-count verification, and compatibility with CPython's free-threaded builds. The repository also includes extensive tests, benchmarks, and CI for multiple architectures and Python implementations (CPython, PyPy, GraalPy).
CodExt is a Python library and command-line tool that extends the standard library's codecs with over 120 custom encodings for data transformation. It provides encoding/decoding functionalities across domains including base encodings (baseN, base45, base85, etc.), cryptography (Vigenère, RSA, XOR), compression (gzip, LZ77/LZ78), steganography, and language-based transformations (Leetspeak, Morse, Braille). The system features a heuristic-based guess mode for automated multi-layered decoding and a macro system for chaining codecs. Architected as a plugin-based library, it allows dynamic registration of new codecs and is designed for CTF, security, and data obfuscation tasks. The codebase demonstrates strong modularity with clear separation of concerns between core functionality, codec implementations, and utility modules.
minimp3 is a minimal, high-performance, ISO-conformant MP3 decoder implemented as a single-header C library (minimp3.h). It provides a low-level frame decoding API and a higher-level streaming/seek API (minimp3_ex.h) with callback-based I/O abstraction. The decoder supports SSE and NEON SIMD acceleration, and compiles to a ~30kB binary with zero external dependencies. The repository includes a comprehensive test suite with over 50 test vectors covering standard and edge-case MPEG audio streams, a fuzzing harness, and a full-featured GUI player (using SDL2 and Nuklear) that demonstrates real-world usage. An additional tool (huffopt) generates optimized Huffman tables for Layer III. The library is designed for embedded systems, game engines, and any environment requiring a lightweight MP3 decoder.