Companies Using Ace

I run the crawler that executes each page's scripts and records which JavaScript globals appear. A domain counts on this page when ace.Editor, ace.EditSession or ace.version exists after load. Our October 2026 crawl puts that at 6,777 domains, 5th of 14 in WYSIWYG Editors, with 3,205 matched to a company. On 16 October 2026 I fetched a random 50 of the 6,774 clean domains, then another 100 from outside the two big platforms, and traced which script file defines Ace on each page.

A code editor in the wrong drawer

Ace's site describes it as an embeddable code editor written in JavaScript, maintained as the primary editor for Cloud9 IDE and released under the BSD license. It highlights code; it doesn't format prose. Our catalog still files it under WYSIWYG Editors, beside Froala, CKEditor and Quill, so its 3.36% share compares it with tools that do another job. I'd rather it sat with CodeMirror and Monaco.

Sales signal: a site that loads Ace on purpose is building software. That is a developer-tools prospect, not a content-team one.

Who puts it on the page

In the random 50, Ace came from Teachable's own scripts on 19 domains, packs served from fedora.teachablecdn.com, and from Salon's site-builder bundle on 4. Sized across the clean set, Teachable accounts for 1,783 domains (26.32%) and Salon for 376 (5.55%). Salon's homepage calls it a way of presenting artwork online, and says the old site stays online until March 2027 now that the platform has been rebuilt. Both are platforms the site owner picked; Ace came along. I count them as bundled, not cut, and keep them in view.

"A quarter of the Ace footprint is course creators on Teachable who never chose a code editor. The platform ships it in every page bundle." - David Thomson, CTO at TechnologyChecker.io

Sales signal: filter out Teachable and Salon before you prospect. What remains, about 4,600 domains, is organisations that chose a code editor.

The rest of the list

In the 100 pages I traced from outside those two platforms, the largest group, about 35, loaded Ace from their own application bundle: dashboards, admin consoles, supplier portals, low-code builders. 14 pulled it from cdnjs, several through a WordPress plugin, and 31 showed no Ace in a static fetch, usually because the app loads it after sign-in or on demand. A few products bundle it for their customers. NHS trusts on VerseOne CMS load plugins/ace/ace.min.js on public pages, and 48 clean domains are nhs.uk hostnames. Ten university portals among our company candidates, the University of Michigan, Pitt and Villanova among them, serve the identical student-portal bundle. Organizr, Concrete CMS, Moodle question types and CYBERBIZ's store admin turn up too, each in small numbers.

Sales signal: when one script file appears on many institutions, sell to the vendor behind it, not the institutions.

Old builds

The rule captures a version on 6,406 of 6,774 domains (94.57%). Ace 1.4.14, from January 2022, leads with 1,889, 1,736 of them Teachable's. Ace 1.2.3, from January 2016, has 578, all 376 Salon sites among them. Then come 1.2.9 (488), 1.4.12 (362) and 1.44.0, the newest release at crawl time (11 May 2026; 1.45.0 followed on 16 October), with 328. In all, 4,387 domains run a build older than 1.5, released in May 2022. Outside Teachable and Salon, 797 of the 4,291 versioned domains run 1.43 or later. Release dates are from the Ace changelog.

Sales signal: a self-built app pinned to a 2017 Ace is an app nobody has touched in years. Front-end modernisation and security review have an opening there.

Who and where

The United States has 1,121 of the 3,205 matched companies, the United Kingdom 235, Germany 153. 52.38% of sized companies have 1 to 10 staff, and 46.03% of those with a founding year started in the 2010s. Software development is 12.95% of matched companies, IT services 7.79% and technology and internet 6.19%. The named rows are application pages: Zscaler's Private Access admin console, Procore's developer site, Renesas's support site and Jefferies' research content site. Of the 50 companies in the table, 36 loaded Ace when I fetched their detection URL.

Sales signal: the developer-portal and admin-console rows are the buyers for API documentation, query tooling and embedded-editor alternatives.

Overlap, not switching

We publish no switching table. 885 domains run Ace and TinyMCE today, 190 Ace and CKEditor, 179 Ace and Quill. They do different jobs on the same page, and most domains ever seen with both still run both, so no pair passed our tests. Since tracking began on 16 March 2026, 1,140 domains dropped Ace on at least one hostname; 62 still load it elsewhere. The month counts rose from 4,091 in June to 6,777 in October, partly because the set of domains we crawl turns over every month, dead sites out and new ones in, and partly because our detection widens.

"Nobody replaces a rich-text editor with Ace. They add it next to one, because one edits copy and the other edits code." - David Thomson, CTO at TechnologyChecker.io

Sales signal: don't pitch Ace users a rich-text editor as a switch; pitch it as the other half of the page.

The stack around it

Across the 6,774 domains, jQuery shows on 81.58%, Google Analytics on 70.53%, Lodash on 57.71%. Ruby on Rails (30.59%), Ahoy (23.69%) and Filestack (8.68%) are largely Teachable's stack. WordPress runs on 22.34%, Next.js on 7.47%, Microsoft ASP.NET on 8.05%.

Sales signal: strip the Teachable rows and the stack turns into custom applications on Rails, ASP.NET and Next.js, the audience for developer tooling.

What it costs

Nothing. Ace is released under the BSD license, and the current 1.45.2 is a free download. The cost is maintenance, which the version numbers above say many sites skip.

Key takeaways

1. 6,777 domains load Ace; it is a code editor filed under WYSIWYG Editors.

2. Teachable bundles it on 1,783 domains (26.32%) and Salon on 376 (5.55%).

3. 4,387 domains run a build older than Ace 1.5; 328 ran 1.44.0, the newest release at crawl time.

4. The deliberate users are software firms, universities and NHS trusts, on application pages.

5. Ace sits beside rich-text editors; nothing switches.

How to use this list

Exclude Teachable and Salon domains, then sort by version and by page type: consoles and developer portals first. The full list of 6,777 domains, with 3,205 matched companies, is on TechnologyChecker.io.