MimeKit is a mature, high-performance .NET library for creating, parsing, and manipulating MIME messages (email). It provides comprehensive support for all standard MIME structures (multipart, message/rfc822, content-transfer encodings), internationalized headers (RFC 2047/2231), and email security features including S/MIME, OpenPGP, DKIM, and ARC signing/verification. The library also includes a full HTML5 tokenizer, TNEF (Outlook Transport Neutral Encapsulation Format) reader, text format converters (HTML, flowed, plain), and a stream filter pipeline for encoding/decoding and line-ending normalization. The codebase is well-architected with clean abstractions (visitor pattern, filter chain, encoder/decoder interfaces), extensive unit tests, and benchmarks demonstrating 25x–75x faster parsing than competing .NET MIME libraries. It is distributed as NuGet packages (MimeKit, MimeKitLite) and is a .NET Foundation project. The repository also includes sample applications for Windows Forms, iOS, and Android, and a DKIM verifier sample.
This is a Go library for detecting the MIME type of files using magic number signatures. It implements a hierarchical detection tree rooted at 'application/octet-stream', allowing precise identification of over 200 file formats without any external dependencies. The library provides three detection entry points (byte slice, reader, file path) and supports concurrency via atomic and mutex locks. It includes custom parsers for CSV, JSON, OLE2/CDF, and MP3 frames, all optimized for performance and zero-copy where possible. The codebase is extensively tested with unit tests, fuzzing, and benchmarks, and is actively maintained with CI/CD, code scanning, and dependency automation. It is a standalone library with no runtime dependencies beyond the Go standard library.
DockYard/elixir-mail is an Elixir library for building, parsing, and rendering email messages according to RFC 2822 and related MIME standards. It provides a composable API to create simple and multipart email messages, handle various transfer encodings (Base64, Quoted-Printable, 7bit, 8bit, binary), and parse incoming email into structured data. The library is structured around a core `Mail.Message` struct with separate modules for encoding, parsing, rendering, and MIME type lookup. It does not require any external runtime dependencies beyond the Erlang/OTP standard library.