# What does Open Source Guides use?

Open Source Guides (opensource.guide) shows public evidence of 11 tools, according to runsonwhat (last checked 2026-11-01).

## Edge & Hosting

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Fastly](https://www.runsonwhat.com/reverse/fastly) | CDN & Edge | Website code |  |
| [NS1](https://www.runsonwhat.com/reverse/ns1) | DNS | DNS records |  |
| [GitHub Pages](https://www.runsonwhat.com/reverse/github-pages) | Hosting & Cloud | DNS records, Website code |  |

## Application

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Google Fonts](https://www.runsonwhat.com/reverse/google-fonts) | Media & UI | Website code |  |

## Data & Observability

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Fathom](https://www.runsonwhat.com/reverse/fathom) | Analytics | Website code |  |

## Go-to-market

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Mailchimp](https://www.runsonwhat.com/reverse/mailchimp) | Marketing | Website code |  |

## Company Ops

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Let's Encrypt](https://www.runsonwhat.com/reverse/letsencrypt) | Security & Compliance | DNS records |  |
| [Sectigo](https://www.runsonwhat.com/reverse/sectigo) | Security & Compliance | DNS records |  |
| [DigiCert](https://www.runsonwhat.com/reverse/digicert) | Security & Compliance | DNS records |  |
| [GitHub](https://www.runsonwhat.com/reverse/github) | Dev Tools | Custom domain |  |

## FAQ

### What tools does Open Source Guides use?

As of November 2026, runsonwhat has found 11 tools at Open Source Guides (opensource.guide) in public records. Edge & Hosting: Fastly, NS1 and GitHub Pages. Application: Google Fonts. Data & Observability: Fathom. Go-to-market: Mailchimp. Company Ops: Let's Encrypt, Sectigo and DigiCert. Last checked November 1, 2026.

### What cloud does Open Source Guides run on?

Open Source Guides uses GitHub Pages for hosting and cloud infrastructure, according to runsonwhat (November 2026). runsonwhat found GitHub Pages through DNS records that point at GitHub Pages and code on opensource.guide. GitHub Pages is used by 4,380 companies runsonwhat tracks.

### What analytics tools does Open Source Guides use?

Open Source Guides uses Fathom for analytics, according to runsonwhat (November 2026). runsonwhat found Fathom through Fathom code on opensource.guide. Fathom is used by 2,655 companies runsonwhat tracks.

### What marketing software does Open Source Guides use?

Open Source Guides uses Mailchimp for marketing, according to runsonwhat (November 2026). runsonwhat found Mailchimp through Mailchimp code on opensource.guide. Mailchimp is used by 117,859 companies runsonwhat tracks.

### Does Open Source Guides use Google Fonts?

Yes. runsonwhat found Google Fonts at Open Source Guides through Google Fonts code on opensource.guide. Google Fonts is a Media & UI tool used by 825,840 companies runsonwhat tracks.

### Which companies have a tech stack similar to Open Source Guides's?

The companies with the stacks most like Open Source Guides' are Go Micro, Zango Global, Deliveroo and Scalix World Private, according to runsonwhat (November 2026). Each shares 3 to 3 tools with Open Source Guides, and rare tools count for more than common ones like Google Workspace, so the match reflects real stack choices.

### How does runsonwhat know what Open Source Guides uses?

runsonwhat reads public records only. Of the 11 tools at Open Source Guides, 5 were found through code on opensource.guide, 5 through DNS records and 1 through subdomains that point at the vendor. A tool is listed only when a direct record backs it up; DNS is rechecked weekly and opensource.guide about monthly.


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Source: runsonwhat, https://www.runsonwhat.com/company/opensource.guide (updated November 2026). Counts are companies with direct public evidence of the tool (DNS records, certificates, website code, a real-browser crawl, subprocessor lists), so they are lower bounds. Methodology: https://www.runsonwhat.com/methodology.