# What does Os33 use?

Os33 (os33.com) shows public evidence of 12 tools, according to runsonwhat (last checked 2026-10-20).

- Industry: Software
- Size: 51–200 employees
- Based in: New York, United States
- Founded: 2010
- LinkedIn: https://www.linkedin.com/company/os33

## Go-to-market

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Mailchimp](https://www.runsonwhat.com/reverse/mailchimp) | Marketing | Email records |  |
| [HubSpot](https://www.runsonwhat.com/reverse/hubspot) | Sales & CRM | Custom domain, Email records |  |
| [Zendesk](https://www.runsonwhat.com/reverse/zendesk) | Support & Docs | Email records |  |
| [Salesforce](https://www.runsonwhat.com/reverse/salesforce) | Sales & CRM | Email records |  |
| [HubSpot CMS](https://www.runsonwhat.com/reverse/hubspot-cms) | Website & CMS | Custom domain |  |

## Company Ops

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Microsoft 365](https://www.runsonwhat.com/reverse/microsoft-365) | Workspace | Email records, DNS verification records |  |
| [Apple Business](https://www.runsonwhat.com/reverse/apple) | Workspace | DNS verification records |  |
| [Atlassian](https://www.runsonwhat.com/reverse/atlassian) | Dev Tools | DNS verification records |  |
| [Mailchimp Transactional](https://www.runsonwhat.com/reverse/mandrill) | Email Delivery | Email records |  |
| [Mailgun](https://www.runsonwhat.com/reverse/mailgun) | Email Delivery | Email records |  |
| [AppRiver](https://www.runsonwhat.com/reverse/appriver) | Security & Compliance | Email records |  |

## FAQ

### What tools does Os33 use?

As of October 2026, runsonwhat has found 12 tools at Os33 (os33.com) in public records. Go-to-market: Mailchimp, HubSpot and Zendesk. Company Ops: Microsoft 365, Apple Business and Atlassian. Last checked October 20, 2026.

### What CRM does Os33 use?

Os33 uses HubSpot for its CRM, alongside Salesforce, according to runsonwhat (October 2026). runsonwhat found HubSpot through a subdomain that points at HubSpot and email records. HubSpot is used by 92,972 companies runsonwhat tracks.

### What email provider does Os33 use?

Os33 uses Microsoft 365 for email and office software, alongside Apple Business, according to runsonwhat (October 2026). runsonwhat found Microsoft 365 through email records that authorize Microsoft 365 and a DNS verification record. Microsoft 365 is used by 706,383 companies runsonwhat tracks.

### What does Os33 use for customer support?

Os33 uses Zendesk for customer support and documentation, according to runsonwhat (October 2026). runsonwhat found Zendesk through email records that authorize Zendesk. Zendesk is used by 41,322 companies runsonwhat tracks.

### What is Os33's website built with?

Os33 uses HubSpot CMS for its website, according to runsonwhat (October 2026). runsonwhat found HubSpot CMS through a subdomain that points at HubSpot CMS. HubSpot CMS is used by 32,993 companies runsonwhat tracks.

### What marketing software does Os33 use?

Os33 uses Mailchimp for marketing, according to runsonwhat (October 2026). runsonwhat found Mailchimp through email records that authorize Mailchimp. Mailchimp is used by 113,899 companies runsonwhat tracks.

### Does Os33 use Atlassian?

Yes. runsonwhat found Atlassian at Os33 through a DNS verification record for Atlassian. Atlassian is a Dev Tools tool used by 65,570 companies runsonwhat tracks.

### How does runsonwhat know what Os33 uses?

runsonwhat reads public records only. Of the 12 tools at Os33, 7 were found through email records, 3 through DNS records and 2 through subdomains that point at the vendor. A tool is listed only when a direct record backs it up; DNS is rechecked weekly and os33.com about monthly.


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Source: runsonwhat, https://www.runsonwhat.com/company/os33.com (updated October 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.