Fonts

With the prevalence of Unicode, many systems render APL legibly out-of-the-box. However, for a uniform appearance, the font should be designed with APL in mind.^[1] This article lists some fonts that are suited for APL, and how to use them.

Monospace

Name (website)	Source (download)	Description
APL2 Unicode	IBM	Straight from IBM typewriter terminals with oblique letters.
APL385 Unicode	Adrian Smith	Inspired by Comic Sans Serif.
APL386 Unicode	GitHub	APL385 Unicode with fewer issues and more accented characters.
BQN386 Unicode	GitHub	Re-hinted APL386 Unicode with harmonised glyphs and support for BQN.
APLX Upright	MicroAPL	A monospaced grotesque font, reminiscent of Akzidenz-Grotesk.
Courier APL2 Unicode	IBM	The classic Courier typewriter font, extended with APL symbols.
DejaVu BQN Sans Mono	GitHub	DejaVu Sans Mono with support for BQN.
DejaVu Sans Mono	GitHub	Wide range of characters with original look and feel of Vera.
DejaVu Sans Mono Bront	GitHub	DejaVu Sans Mono tweaked to be better geared for programming.
DejaVu Sans Mono Nerd	AUR	DejaVu Sans Mono patched with a high number of extra glyphs.
Everson Mono	Evertype (shareware)	A simple font, quite legible at sizes as small as 4 points.
Fairfax	KreativeKorp	Regular/Bold/Italic 6×12 bitmap font supporting many characters.
Fairfax Serif	KreativeKorp	Serif 6×12 bitmap font supporting many characters.
Fairfax HD	KreativeKorp	Plotter-like font supporting many characters.
IBM 3270	GitHub	Modern version of a classic IBM terminal font.
Iosevka Anonymous Pro Style	GitHub	A slender, highly customisable monospace sans-serif and slab-serif typeface inspired by Pragmata Pro, M+ and PF DIN Mono. This list includes seven ready-made versions, but it is easy to build one's own version too. When compiling, it is possible to configure character variants with `apl-form = 'enable'` to prioritise harmonising APL glyphs.
Iosevka Fira Mono Style	GitHub
Iosevka Pragmata Pro Style	GitHub
Iosevka Source Code Pro Style	GitHub
Iosevka JetBrains Mono Style	GitHub
Iosevka IBM Plex Mono Style	GitHub
Iosevka Recursive Mono Style	GitHub
poultreMono	Codeberg	A 5×9 pixel font.
PragmataPro	(commercial)	A condensed font optimized for coding, mathematics and engineering.
SAX2	GitHub	Curly font with italic letters, based on Sharp APL for Unix.
SImPL	Vector	Courier-based, but thicker.
Unifont	Unifoundry	Low-resolution bitmap fall-back font

Proportional

Name (website)	Source (download)	Description
APL333	Adrian Smith	Proportionally spaced version of APL385 Unicode
Code2000	FontSpace	Wedge-serif pan-Unicode font.
Iosevka Aile	GitHub	Proportionally spaced version of Iosevka.
Iosevka Etoile	GitHub	Proportionally spaced slab-serif version of Iosevka.
Quivira	Website	Serif font supporting many symbols, similar to Garamond.
Segoe UI Symbol	(commercial)	Microsoft's humanist interface and corporate font.
Stix Two Math	GitHub	Serif font, broadly compatible with Times New Roman.
Symbola	UFAS (free for personal non-commercial use only)	Supporting many scripts and symbols, similar to Computer Modern.

The APL typeball

Historical anecdote

Using IBM's APL\360 required the use of the IBM 2741 or IBM 1050 printing terminal with an APL type ball. The APL2741 font is based directly on this type ball.

Rendering APL on websites

For APL code to be rendered well on a website, three conditions must be fulfilled:

The page has to use a proper encoding
The APL code has to be formatted with an appropriate APL font
The APL font has to be made available for those users that do not have it installed

All these things can be achieved by inserting the following into the <head> element of the page (replace font name and file name with desired font):

<meta charset="UTF-8">
<style>
  @font-face{
    font-family: APL; src: local("APL385 Unicode"), url(Apl385.ttf)
  }
  pre, code {
    font-family: APL
  }
</style>

The Apl385.ttf file must then be placed in the same directory as the HTML file, and all APL code must be wrapped in <pre> or <code> elements.

Changing font in Dyalog RIDE

Dyalog Ltd's cross-platform RIDE interface, which is the default GUI interface on all non-Windows platforms, does not expose a font setting. However, it is trivial to change font:

Open ride-base.css*
Find the line that says src: url('./fonts/Apl385.woff') format('woff'), url('./fonts/Apl385.ttf') format('truetype');
Insert local('font name'), immediately after src:, for example src: local('SAX2'), url('./fonts/Apl385.woff') format('woff'), url('./fonts/Apl385.ttf') format('truetype');
Restart RIDE

* The full path to ride-base.css varies (examples for RIDE 4.4 and Dyalog 18.2):

Stand-alone installation:
- Windows: %LOCALAPPDATA%\Programs\Dyalog\Ride-4.4\resources\app\style\ride-base.css
- Linux: /opt/ride-4.4/resources/app/style/ride-base.css
- macOS: /Applications/Ride-4.4.app/resources/app/style/ride-base.css
Zero-footprint RIDE (served by the interpreter and normally accessed through a browser):
- Linux or AIX: /opt/mdyalog/18.2/64/unicode/Contents/Resources/Dyalog/RIDEapp/resources/app/style/ride-base.css
- macOS: /Applications/Dyalog-18.2.app/Contents/Resources/Dyalog/RIDEapp/resources/app/style/ride-base.css

References

↑ Phil Chastney: APL fonts are different

APL development [edit]
Interface	Session ∙ Typing glyphs (on Linux) ∙ Fonts ∙ Text editors
Publications	Introductions ∙ Learning resources ∙ Simple examples ∙ Advanced examples ∙ Mnemonics ∙ ISO 8485:1989 ∙ ISO/IEC 13751:2001 ∙ A Dictionary of APL ∙ Case studies ∙ Documentation suites ∙ Books ∙ Papers ∙ Videos ∙ APL Quote Quad ∙ Vector journal ∙ Terminology (Chinese, German) ∙ Neural networks ∙ Error trapping with Dyalog APL (in forms)
Sharing code	Backwards compatibility ∙ APLcart ∙ APLTree ∙ APL-Cation ∙ Dfns workspace ∙ Tatin ∙ Cider
Implementation	Resources ∙ Open-source ∙ Magic function ∙ Performance ∙ APL hardware
Developers	Timeline of corporations ∙ APL2000 ∙ Dyalog ∙ IBM ∙ IPSA ∙ STSC

[1] Phil Chastney: APL fonts are different

[1]