Install oksh with Homebrew, apk, dnf, MacPorts, Nix

Project links

• Homepage

Commands and aliases

• oksh

Project history

The deeper lineage starts with pdksh. OpenBSD's `bin/ksh` README says pdksh was a mostly complete AT&T ksh look-alike, maintained by Michael Rendell after earlier maintainers Simon J. Gerraty, John R. MacMillan, and Eric Gisin. The CONTRIBUTORS file records Gisin creating pdksh from Charles Forsyth's public-domain V7 shell with pieces from the BRL shell around 1987 to 1989.

oksh turns OpenBSD's maintained ksh into a portable project. Its repository was created on 2015-01-06, and the README states that it is not an official OpenBSD project. The stated reason is simple and opinionated: all operating systems deserve a good shell.

The project is intentionally conservative about behavior. The README asks contributors to send behavior changes upstream to OpenBSD tech@ first, and says oksh will sync with upstream OpenBSD code once a patch is accepted there. Portability changes are welcome in oksh; shell semantics belong upstream.

Adoption history

oksh's adoption is mostly among users and distributors who want OpenBSD ksh outside OpenBSD. The README lists support across OpenBSD, the BSDs, macOS, glibc and musl Linux, Cygwin, Android via Termux, AIX, IBM i PASE, Solaris, Illumos, WSL, Haiku, SerenityOS, MSYS2, QNX, and more. It also records many tested C compilers, from clang and gcc to pcc, cparser, tcc, CompCert, chibicc, and other niche compilers.

Package-manager coverage is broad for a small shell. The input metadata includes apk, Homebrew, dnf, MacPorts, and Nix. Homebrew's 2026-07-01 formula API reported 121 installs over 365 days, and the upstream README links package status via Repology.

How it is used

Users install oksh when they want the OpenBSD ksh command language and interactive shell on a non-OpenBSD system. It can act as an interactive login shell or as a script interpreter for ksh-style scripts, while retaining the OpenBSD/pdksh flavor rather than tracking AT&T ksh93.

Builders use the provided `configure` script and POSIX Makefile path. The README documents native builds, out-of-tree builds, cross compilation with `--no-thanks`, optional ncurses support for screen-clearing routines, and a design goal of remaining self-contained.

Why package nerds care

oksh is significant because it is a living portability layer around a base-system shell. It gives package managers a way to ship OpenBSD ksh semantics on platforms where `/bin/ksh` may be missing, old, or from a different lineage.

Its licensing is also package-nerd-friendly but nontrivial: the main Korn shell files are public domain, while portability files are BSD or ISC licensed. Homebrew reflects that as `LicenseRef-Homebrew-public-domain AND BSD-3-Clause AND ISC`.

Timeline

• 1987-1989: Eric Gisin created pdksh using Charles Forsyth's public-domain V7 shell as a base and parts of the BRL shell.
• 1994-07: Michael Rendell took over pdksh maintenance, according to OpenBSD's CONTRIBUTORS file.
• 1999-07: OpenBSD's ksh README was last updated for pdksh 5.2.14.
• 2015-01-06: the `ibara/oksh` repository was created.
• 2026-06-10: oksh-7.9 was published on GitHub.
• 2026-07-01: Homebrew's formula API reported stable version 7.9.

Related projects

• oksh is directly related to OpenBSD ksh and pdksh. It also sits near other ksh-family ports such as loksh and mksh, but oksh's packaging identity is the portable, self-contained OpenBSD ksh line.

Sources

• https://api.github.com/repos/ibara/oksh
• https://formulae.brew.sh/api/formula/oksh.json
• https://github.com/ibara/oksh
• https://github.com/ibara/oksh/releases/tag/oksh-7.9
• https://raw.githubusercontent.com/ibara/oksh/main/README.md
• https://raw.githubusercontent.com/openbsd/src/master/bin/ksh/CONTRIBUTORS
• https://raw.githubusercontent.com/openbsd/src/master/bin/ksh/LEGAL
• https://raw.githubusercontent.com/openbsd/src/master/bin/ksh/README