Re: Factor

Factor: the language, the theory, and the practice.

Factor 0.101 now available

Monday, December 8, 2025

#release

“Keep thy airspeed up, lest the earth come from below and smite thee.” - William Kershner

I’m very pleased to announce the release of Factor 0.101!

OS/CPU Windows Mac OS Linux
x86 0.101 0.101
x86-64 0.101 0.101 0.101

Source code: 0.101

This release is brought to you with almost 700 commits by the following individuals:

Aleksander Sabak, Andy Kluger, Cat Stevens, Dmitry Matveyev, Doug Coleman, Giftpflanze, John Benediktsson, Jon Harper, Jonas Bernouli, Leo Mehraban, Mike Stevenson, Nicholas Chandoke, Niklas Larsson, Rebecca Kelly, Samuel Tardieu, Stefan Schmiedl, @Bruno-366, @bobisageek, @coltsingleactionarmyocelot, @inivekin, @knottio, @timor

Besides some bug fixes and library improvements, I want to highlight the following changes:

  • Moved the UI to render buttons and scrollbars rather than using images, which allows easier theming.
  • Fixed HiDPI scaling on Linux and Windows, although it currently doesn’t update the window settings when switching between screens with different scaling factors.
  • Update to Unicode 17.0.0.
  • Plugin support for the Neovim editor.

Some possible backwards compatibility issues:

  • The argument order to ltake was swapped to be more consistent with words like head.
  • The environment vocabulary on Windows now supports disambiguating f and "" (empty) values
  • The misc/atom folder was removed in favor of the factor/atom-language-factor repo.
  • The misc/Factor.tmbundle folder was removed in favor of the factor/factor.tmbundle repo.
  • The misc/vim folder was removed in favor of the factor/factor.vim repo.
  • The http vocabulary request tuple had a slot rename from post-data to data.
  • The furnace.asides vocabulary had a slot rename from post-data to data, and might require running ALTER TABLE asides RENAME COLUMN "post-data" TO data;.
  • The html.streams vocabulary was renamed to io.streams.html
  • The pdf.streams vocabulary was renamed to io.streams.pdf

What is Factor

Factor is a concatenative, stack-based programming language with high-level features including dynamic types, extensible syntax, macros, and garbage collection. On a practical side, Factor has a full-featured library, supports many different platforms, and has been extensively documented.

The implementation is fully compiled for performance, while still supporting interactive development. Factor applications are portable between all common platforms. Factor can deploy stand-alone applications on all platforms. Full source code for the Factor project is available under a BSD license.

New libraries:

Improved libraries:

Removed libraries

  • ui.theme.images

VM Improvements:

  • More work on ARM64 backend (fix set-callstack, fix generic dispatch)