andmartinelli 

Provides an almost drop-in replacement for String, with allocation-free substring/split methods, along with a ToStringCached() extension method that can be used on StringBuilders, ValueStrings and so on.

Additional System.Drawing APIs for netstandard .NET Standard

Excel spreadsheet (xlsx) manipulation library

Low-allocation version of DiffMatchPatch

Creates fast, strongly typed delegates for accessing methods, fields and properties. The right overload is automatically chosen based on the type arguments of Func<> or Action<>.

SevenZipSharp for netstandard and a few bug fixes.

An optimized version of HtmlAgilityPack with many bug fixes and improvements. Improved features: * Minimizes heap allocations and avoids duplicate strings in the heap * HtmlAttribute, HtmlAttributeCollection, HtmlNodeCollection are now structs * Proper encoding/unencoding of attributes * Fixed... More information

Provides an almost drop-in replacement for System.IO.File, optimized for a very large number of small files. Data is batched in package files, and can be read sequentially.

HTTP and HTML processing library

Low-allocation version of Snowball stemmers.

Shaman.Configuration.Metadata

Utils for efficiently reading from streams of UTF8 text. Commonly used types: Utf8StreamReader, Utf8StreamWriter, CsvReader, SqlDumpReader, Utf8StringCache, Utf8StringExtensions, Utf8Utils, MemoryBuffer, Scratchpad.

JSON/Protobuf serialization utilities, and console/CSV output support

Npgsql is a .NET data provider for PostgreSQL, 100% implemented in C# code. PostgreSQL 9.x and above is officially supported, other versions may work.

Misc extension methods: CaptureBetween, CaptureAfter, CaptureBefore, RecursiveEnumeration, In.

Shaman.DbLinq

Provides wrappers for executing external processes, capturing their stdout, and automatically checking their exit code.

Shaman.Fizzler

Strong named, netstandard-compatible version of CurlSharp.

Filesystem-related utilities