This is an industrial-strength monadic parser combinator library. Megaparsec is a feature-rich package that strikes a nice balance between speed, flexibility, and quality of parse errors.

This Haskell package provides extras for the ghc-contravariant package.

This package provides a compatibility layer for using GHC call stacks with different versions of the compiler.

This package contains an implementation of a high-quality splittable pseudorandom number generator. The generator is based on a cryptographic hash function built on top of the ThreeFish block cipher. See the paper "Splittable Pseudorandom Number Generators Using Cryptographic Hashing" by Claessen, Pałka for details and the rationale of the design.

This library provides a pure Haskell implementation of the Unicode Collation Algorithm described at http://www.unicode.org/reports/tr10/. It is not as fully-featured or as performant as text-icu, but it avoids a dependency on a large C library. Locale-specific tailorings are also provided.

This package provides a type-safe tool for generating XML code via quasi-quoting built on top of ghc-shakespeare.

This library provides Haskell bindings to the Zstandard compression algorithm, a fast lossless compression algorithm targeting real-time compression scenarios at zlib-level and better compression ratios.

Cairo is a library to render high quality vector graphics. There exist various backends that allows rendering to Gtk windows, PDF, PS, PNG and SVG documents, amongst others.

This Haskell library provides strict left folds that stream in constant memory, and you can combine folds using Applicative style to derive new folds. Derived folds still traverse the container just once and are often as efficient as hand-written folds.

This package provides a Haskell module for creating 2D and 3D plots using gnuplot.

This package provides both mutable and immutable Bloom filter data types, along with a family of hash functions and an easy-to-use interface.

The HMatrix package provides a Haskell library for dealing with linear systems, matrix decompositions, and other numerical computations based on BLAS and LAPACK.

Skylighting is a syntax highlighting library with support for over one hundred languages. It derives its tokenizers from XML syntax definitions used by KDE's KSyntaxHighlighting framework, so any syntax supported by that framework can be added. An optional command-line program is provided. Skylighting is intended to be the successor to highlighting-kate.

This package implements the bijection between JSON and CBOR defined in the CBOR specification, RFC 7049.

The premise of basic-prelude is that there are a lot of very commonly desired features missing from the standard Prelude, such as commonly used operators (<$> and >=>, for instance) and imports for common datatypes (e.g., ByteString and Vector). At the same time, there are lots of other components which are more debatable, such as providing polymorphic versions of common functions.

So basic-prelude is intended to give a common foundation for a number of alternate preludes. The package provides two modules: CorePrelude provides the common ground for other preludes to build on top of, while BasicPrelude exports CorePrelude together with commonly used list functions to provide a drop-in replacement for the standard Prelude.

Users wishing to have an improved Prelude can use BasicPrelude. Developers wishing to create a new prelude should use CorePrelude.

This library contains simple and easy-to-use primitives for I/O using streams.

Derive instances of Arbitrary for QuickCheck, with various options to customize implementations.

Automating the arbitrary boilerplate also ensures that when a type changes to have more or fewer constructors, then the generator either fixes itself to generate that new case (when using the uniform distribution) or causes a compilation error so you remember to fix it (when using an explicit distribution).

This package also offers a simple (optional) strategy to ensure termination for recursive types: make Test.QuickCheck.Gen's size parameter decrease at every recursive call; when it reaches zero, sample directly from a trivially terminating generator given explicitly (genericArbitraryRec and withBaseCase) or implicitly (genericArbitrary').

This package provides a set of helper programs necessary to build the Gtk2Hs suite of libraries. These tools include a modified c2hs binding tool that is used to generate FFI declarations, a tool to build a type hierarchy that mirrors the C type hierarchy of GObjects found in glib, and a generator for signal declarations that are used to call back from C to Haskell. These tools are not needed to actually run Gtk2Hs programs.

Zstandard compression packaged as a conduit. This is a very thin wrapper around the official hs-zstd interface.

This package provides functions to prevent or capture writing to stdout and other handles.

Haskell98 invariant functors (also known as exponential functors). For more information, see Edward Kmett's article Rotten Bananas.

Hslogger lets each log message have a priority and source be associated with it. The programmer can then define global handlers that route or filter messages based on the priority and source. It also has a syslog handler built in.

This package contains basic definitions related to indexed profunctors. These are primarily intended as internal utilities to support the optics and generic-lens package families.

This Haskell package provides compatibility layer for ghc-aeson.