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Install crf++ with Homebrew

Conditional random fields for segmenting/labeling sequential data. Version 0.58 via Homebrew; verified 2026-07-24.

Install commandSecurity notes

install

Additional install commands

macOS

Homebrewverified · 100%
brew install crf++

local Homebrew formula metadata

overview

Package summary

Conditional random fields for segmenting/labeling sequential data

Commands and aliases

  • crf_learn
  • crf_test

history

Project history and usage

CRF++ is Taku Kudo's open-source Conditional Random Fields toolkit for segmenting and labeling sequential data. Its official page positions it as a generic-purpose CRF implementation for natural-language-processing tasks such as named entity recognition, information extraction, and text chunking.

Project history

The official CRF++ page lists the first release, version 0.1, on 2005-05-28. The release history shows a steady 2005-2007 development period with API work, parallel training, MIRA training, language bindings, L1 regularization, and a license change to LGPL/BSD dual licensing.

Adoption history

CRF++ became a familiar package for NLP users because it combined a command-line learner and tester, a template-based feature system, and bindings for several languages. Later releases focused on compatibility and maintenance, including GCC, libtool, C++11, Windows, and model-loading fixes.

How it is used

Users prepare training and test files plus feature templates, train models with crf_learn, and decode with crf_test. The package is especially associated with sequence-labeling experiments where researchers want a compact C++ CRF implementation available from source or OS packages.

Why package nerds care

For package maintainers, CRF++ is a classic NLP C++ library/CLI: old enough to need build-system care, small enough to package directly, and still recognizable because many downstream tutorials and research pipelines refer to crf_learn and crf_test.

Timeline

  • 2005-05-28: CRF++ 0.1 released
  • 2006-03-30: Version 0.41 added parallel training
  • 2006-11-26: Version 0.45 added 1-best MIRA training
  • 2007-02-12: Version 0.46 changed license to LGPL/BSD dual license and added Perl, Ruby, Python, and Java bindings
  • 2007-07-07: Version 0.48 added L1-CRF support
  • 2013-02-13: CRF++ 0.58 released

Related projects

  • CRF++ is related to later CRF sequence-labeling packages such as CRFsuite, which explicitly compares its data-format flexibility with CRF++.

security posture

Risk level: green

narrow executable package without higher-risk signals.

Risk classifier

green risk · low confidence · appliance

Why

  • narrow executable package without higher-risk signals

Signals

  • metadata:no-higher-risk-signals

Install behavior

  • No Homebrew post-install hook is recorded in formula metadata.
  • Homebrew bottle metadata is available for 13 platform targets.

Recommended review

Before unattended agent use, check whether the tool reads plaintext credentials, writes remote state, publishes artifacts, or shells out to plugins.

executables

Installed executables

CommandKindExposureNote
crf_learncliglobal executable
crf_testcliglobal executable

freshness

Version and freshness

These signals separate page generation age, package-manager activity, and upstream release comparison. Version lag is warned only when an evidence URL and comparable versions are present.

page generated2026-08-04
manager version0.58
manager updated2026-07-24
local dataok
upstreamnot checked
latest detectednot detected

https://taku910.github.io/crfpp/

install metadata

Package metadata

Package keybrew:crf++
Version0.58
Package managerHomebrew
Package manager pagehttps://formulae.brew.sh/formula/crf++
Homepagehttps://taku910.github.io/crfpp/
Repositoryhttps://github.com/taku910/crfpp
Upstream docshttps://taku910.github.io/crfpp/
LicenseLGPL-2.1-only OR BSD-3-Clause
Source archivehttps://mirrors.sohu.com/gentoo/distfiles/f2/CRF%2B%2B-0.58.tar.gz
Last updated2026-07-24T20:11:30+09:00
Pulseupdated
Bottleavailable (on arm64_big_sur, arm64_linux, arm64_monterey, arm64_sequoia, arm64_sonoma, arm64_tahoe, arm64_ventura, big_sur, catalina, monterey, sonoma, ventura, x86_64_linux)
Homebrew post-installnot defined
Servicenone declared

registry facts

Source database details

Source DatabaseHomebrew formula API
Taphomebrew/core
Full Namecrf++
Version Scheme0
Revision0
Head VersionHEAD
Bottle Stable Root URLhttps://ghcr.io/v2/homebrew/core
Deprecatedno
Disabledno
Keg Onlyno
URL Keys
  • head
  • stable

package graph

Links come from deterministic package relationships, av.db category and tag curation, ecosystem matches, and package hub membership.

Related tools

  • cabochaPopular package that depends on this formula.

Same workflow

  • dvcShares pkgdb curated category or tags: cli, developer-tools, machine-learning.
  • hunspellShares pkgdb curated category or tags: cli, developer-tools, nlp.
  • scwsShares pkgdb curated category or tags: cli, developer-tools, nlp.
  • crfsuiteShares pkgdb curated category or tags: cli, conditional-random-fields, machine-learning, nlp, sequence-labeling.
  • beneratorLocal metadata places this package in an adjacent workflow. Shared terms: cli, data, developer, developer-tools, test.
  • csmithLocal metadata places this package in an adjacent workflow. Shared terms: cli, developer, developer-tools, random, test.

source trail

Generated from repository data

This page is generated by av-web from the private package SQLite artifact built by scripts/generate-pkg-sqlite.py.

Used sources

  • Geiger risk classifier
  • cross-ecosystem install command graph
  • curated package history
  • package relationship graph
  • package version freshness
  • package-page enrichment
  • pkg.so package database
  • pkgdb category and tag curation