CentOS VS POSIX
As of 30 October 2026, POSIX is named by 103 companies and CentOS by 564; CentOS skews to companies under 200 people (50% vs 35%), POSIX to companies over 1,000 (29% vs 25%).
As of 30 October 2026 · refreshed daily · counts move as websites, DNS and career sites are re-read.
The website-and-DNS footprint is not comparable between a marketing suite and a CRM: CentOS's script and mail records show on hundreds of thousands of small sites, POSIX rarely leaves a trace outside its own apps. Compare on the job-posting numbers; use the footprint for reach.
- CentOS: 2–200 employees
- 50%
- POSIX: 2–200 employees
- 35%
- CentOS: 1,000+ employees
- 25%
- POSIX: 1,000+ employees
- 29%
- Postings per company, 90 days
- 2.4 · 2.1
- Website or DNS footprint
- 0 · 0
Who chooses which
Share of each tool's companies in every segment. "Leans" marks a gap of more than two points.
| Segment | CentOS | share | POSIX | share | Leans |
|---|---|---|---|---|---|
| Self-employed | 6 | 1% | – | – | outside top 12 |
| 2-10 employees | 36 | 6% | 5 | 5% | even |
| 11-50 employees | 105 | 19% | 16 | 16% | CentOS |
| 51-200 employees | 142 | 25% | 15 | 15% | CentOS |
| 201-500 employees | 75 | 13% | 20 | 19% | POSIX |
| 501-1000 employees | 57 | 10% | 17 | 17% | POSIX |
| 1001-5000 employees | 62 | 11% | 13 | 13% | even |
| 5001-10000 employees | 18 | 3% | 6 | 6% | POSIX |
| 10,001+ employees | 63 | 11% | 11 | 11% | even |
| Segment | CentOS | share | POSIX | share | Leans |
|---|---|---|---|---|---|
| Technology & software | 318 | 56% | 46 | 45% | CentOS |
| Business & finance services | 85 | 15% | 8 | 8% | CentOS |
| Manufacturing & industry | 66 | 12% | 30 | 29% | POSIX |
| Utilities & infrastructure | 21 | 4% | 3 | 3% | even |
| Media & content | 16 | 3% | 4 | 4% | even |
| Public, community & associations | 13 | 2% | 2 | 2% | even |
| Consumer services & leisure | 13 | 2% | 3 | 3% | even |
| Commerce & trade | 9 | 2% | 2 | 2% | even |
| Property & construction | 7 | 1% | – | – | outside top 12 |
| Health care | 5 | 1% | 1 | 1% | even |
| Automotive | 4 | 1% | 3 | 3% | POSIX |
| Transport, logistics & rental | 4 | 1% | 1 | 1% | even |
| Segment | CentOS | share | POSIX | share | Leans |
|---|---|---|---|---|---|
| United States | 321 | 57% | 72 | 70% | POSIX |
| United Kingdom | 38 | 7% | 6 | 6% | even |
| France | 33 | 6% | 1 | 1% | CentOS |
| India | 25 | 4% | 4 | 4% | even |
| Germany | 22 | 4% | 5 | 5% | even |
| Singapore | 12 | 2% | – | – | outside top 12 |
| Netherlands | 10 | 2% | – | – | outside top 12 |
| Canada | 8 | 1% | 3 | 3% | even |
| Italy | 8 | 1% | – | – | outside top 12 |
| Poland | 8 | 1% | – | – | outside top 12 |
| Japan | 6 | 1% | – | – | outside top 12 |
| Spain | 5 | 1% | – | – | outside top 12 |
| Sweden | – | – | 2 | 2% | outside top 12 |
| Austria | – | – | 1 | 1% | outside top 12 |
| Australia | – | – | 1 | 1% | outside top 12 |
| Belgium | – | – | 1 | 1% | outside top 12 |
| Bulgaria | – | – | 1 | 1% | outside top 12 |
| Denmark | – | – | 1 | 1% | outside top 12 |
| Segment | CentOS | share | POSIX | share | Leans |
|---|---|---|---|---|---|
| IT operations & business systems | 935 | 46% | 33 | 9% | CentOS |
| Software engineering | 609 | 30% | 198 | 56% | POSIX |
| Engineering (non-software) | 110 | 5% | 8 | 2% | CentOS |
| Customer service & success | 67 | 3% | – | – | outside top 12 |
| Data & AI | 21 | 1% | 13 | 4% | POSIX |
| Product, program & project management | 13 | 1% | 3 | 1% | even |
| Sales | 10 | 0% | 7 | 2% | even |
| Quality, safety & environment | 6 | 0% | 13 | 4% | POSIX |
| Marketing & communications | 5 | 0% | – | – | outside top 12 |
| Education & training | 4 | 0% | 1 | 0% | even |
| Administration & office | 3 | 0% | – | – | outside top 12 |
| General management & consulting | 2 | 0% | – | – | outside top 12 |
| Logistics warehouse and transport | – | – | 2 | 1% | outside top 12 |
| Skilled trades and field service | – | – | 2 | 1% | outside top 12 |
| Business development & strategy | – | – | 1 | 0% | outside top 12 |
| Manufacturing and production | – | – | 1 | 0% | outside top 12 |
The companies behind each column
Companies using CentOS →
Companies using POSIX →
linux unix ranked →
Quote the sentence with the date and the link. The numbers change daily; the link always shows the current ones.
POSIX is named by 103 companies in job postings and CentOS by 564; 0 name both. (Breaknorm, 30 October 2026, https://breaknorm.co/compare/centos-vs-posix)
Read from the source, not self-reported
Every number on this page can be traced to a page we crawled or a posting we read. Full methodology →
- Job postingsRead hourly from career sites. A tool counts when the employer's own text names it as the team's system; both tools can count for one company.
- Website and DNSScripts and embeds on the company's pages, plus SPF, DKIM, MX and CNAME records of its domain that point at the vendor.
- SegmentsCountry, size and industry from the company profile built from its website.
- Not a reviewNo ratings, prices or feature claims. For those, read the vendors.
CentOS vs POSIX: questions
Which is more used, CentOS or POSIX?
By companies naming it in their own job postings, CentOS (564) over POSIX (103). By website-and-DNS footprint, POSIX (0 vs 0), because its scripts and mail records sit on many small company sites.
Who chooses CentOS?
50% of CentOS companies have 2 to 200 employees, against 35% for POSIX. 25% of CentOS companies have over 1,000 employees, against 29% for POSIX.
Do companies run both?
0 companies name both in their postings, usually CentOS in marketing and POSIX in sales, or during a migration.
Where do these numbers come from?
From the employer's own text in job postings read hourly from career sites, and from scripts found on company websites in our crawl. No vendor data, no surveys.
Get either list your way
The same data as a search, over MCP and the API, as bulk files, or pushed to you as it changes.
Every company on either tool,
with the person who owns it
Filter on CentOS or POSIX. Start free, no card.