Technology answer

ef.js

123

companies run it, <0.01% of 54,527,857 in the index. Landing 12 Sept 2026.

Hosts: 394 live hosts run it, of 191,809,695 hosts in the index, <0.01%. A host is a website, not a company.

Companies by month

No published series

123 companies is under the publication floor of 1,000, and the fixed panel anchored at 31 Dec 2020 carries 27 of them. A monthly line drawn off that many observations would be noise at the same weight as a line off millions, so this page states the count and its date and publishes no series.

First discovered 26 Apr 2020, last discovered 10 Sept 2026.

Both denominators, and a third

Shares of the same 123each row a different wholelanding 12 Sept 2026

Denominator

Companies

Share

companies in the index

54,527,857

<0.01%

companies running anything in JavaScript Frameworks

13,886,915

<0.01%

companies running anything in Component-based UI frameworks

11,820,258

<0.01%

Three wholes, three shares of one count: a share travels with its whole, never alone. Against the last of them, ef.js is rank 24 of 32 technologies in Component-based UI frameworks.

Open as a segment

123 companies; add a country, a sector or a band on the segment page. Counting is free.

/companies/tech-ef-js

Open the segment

Catalogue record

As recorded in the cataloguetaxonomy release tax-2026.10last discovered 10 Sept 2026

An open-source lightweight JavaScript framework for building reactive UIs.

ef.js is a small framework that provides reactive bindings and component-style development for web interfaces. It is open source and used by developers seeking a minimal MVVM-style toolkit.

Kindlibrary

Vendoref.js project, ef.js.org

PathWeb Engineering > JavaScript Frameworks > Component-based UI frameworks

Slugef-js

Deploymentself-hosted

Pricingfree

Open sourceyes

First discovered2020-04-26

Last discovered2026-09-10

Taxonomy releasetax-2026.10

One click under this answer

Subcategory answerComponent-based UI frameworksCompanies running anything in Component-based UI frameworks, 11,820,258 of 54,527,857 in the index, and the technologies ranked in it.Category answerJavaScript FrameworksThe category above this one, with its subcategories and the companies in each.CatalogueAll 8,177 technologiesRanked by the companies running them, with the publication gate named and the long tail drawn.