POSIX alternatives
As of 4 November 2026, 28 linux unix are named by companies instead of POSIX: Linux by 15,946 companies, Unix by 2,662, Red Hat Enterprise Linux by 2,259.
As of 4 November 2026 · refreshed daily · counts move as websites, DNS and career sites are re-read.
- POSIX, companies in postings
- 140
- Most used alternative
- Linux · 15,946
- Fastest hiring, 90 days
- Linux
- Alternatives ranked
- 28
- Catalogue
- T-1.0.1-prov
linux unix companies choose instead of POSIX
Companies naming each tool in their own postings, and postings in the last 90 days. Bars are relative to the category leader.
| # | Alternative | Companies | companies | vs POSIX | postings, 90 d | Compare |
|---|---|---|---|---|---|---|
| 1 | LinuxLinux Foundation | 15,946 | 11390% | 83,661 | POSIX vs Linux → | |
| 2 | UnixThe Open Group | 2,662 | 1901% | 9,172 | POSIX vs Unix → | |
| 3 | Red Hat Enterprise LinuxRed Hat | 2,259 | 1614% | 9,445 | POSIX vs Red Hat Enterprise Linux → | |
| 4 | UbuntuCanonical | 1,521 | 1086% | 3,441 | POSIX vs Ubuntu → | |
| 5 | CentOSRed Hat | 765 | 546% | 1,664 | POSIX vs CentOS → | |
| 6 | DebianDebian Project | 722 | 516% | 1,314 | POSIX vs Debian → | |
| 7 | IBM AIXIBM | 383 | 274% | 843 | POSIX vs IBM AIX → | |
| 8 | Oracle SolarisOracle | 339 | 242% | 1,126 | POSIX vs Oracle Solaris → | |
| 9 | eBPFLinux Foundation | 284 | 203% | 933 | POSIX vs eBPF → | |
| 10 | 259 | 185% | 412 | POSIX vs cron → | ||
| 11 | SUSE LinuxSUSE | 230 | 164% | 727 | POSIX vs SUSE Linux → | |
| 12 | Rocky LinuxRocky Enterprise Software Foundation | 208 | 149% | 529 | POSIX vs Rocky Linux → | |
| 13 | 177 | 126% | 434 | POSIX vs SELinux → | ||
| 14 | AlmaLinuxAlmaLinux OS Foundation | 143 | 102% | 204 | soon | |
| 15 | Oracle LinuxOracle | 98 | 70% | 351 | soon | |
| 16 | systemdsystemd project | 83 | 59% | 194 | soon | |
| 17 | Amazon LinuxAmazon Web Services | 64 | 46% | 248 | soon | |
| 18 | AppArmorCanonical | 59 | 42% | 110 | soon | |
| 19 | HP-UXHewlett Packard Enterprise | 53 | 38% | 120 | soon | |
| 20 | FedoraFedora Project | 52 | 37% | 178 | soon | |
| 21 | FreeBSDFreeBSD Foundation | 52 | 37% | 339 | soon | |
| 22 | NixOSNixOS Foundation | 50 | 36% | 210 | soon | |
| 23 | dmesgLinux Foundation | 44 | 31% | 74 | soon | |
| 24 | journalctlsystemd project | 37 | 26% | 46 | soon | |
| 25 | eXpress Data Path (XDP)Linux Foundation | 37 | 26% | 78 | soon | |
| 26 | ext4Linux kernel community | 24 | 17% | 52 | soon | |
| 27 | grepGNU Project | 21 | 15% | 36 | soon | |
| 28 | auditdLinux Foundation | 17 | 12% | 41 | soon |
Filter on any of them, or on POSIX users who also name an alternative, and open the person who owns the stack.
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28 linux unix are named by companies instead of POSIX: Linux by 15,946 companies, Unix by 2,662, Red Hat Enterprise Linux by 2,259, measured from their own job postings. (Breaknorm, 4 November 2026, https://breaknorm.co/tools/posix/alternatives)
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 →
- RankingCompanies whose own postings name the tool as the team's system, from the Breaknorm technology catalogue T-1.0.1-prov. Editions are folded into their parent product.
- 90-day postingsOpen postings first seen or posted in the last 90 days that name the tool.
- Not includedRatings, prices, feature claims, sponsored positions.
POSIX alternatives: questions
What is the most used alternative to POSIX?
Linux: 15,946 companies name it in their own job postings, against 140 for POSIX.
How is this list ranked?
By the number of companies whose own postings name the tool as the team's system (Breaknorm technology catalogue T-1.0.1-prov), then by postings in the last 90 days. No ratings, no vendor input, no sponsored positions.
Does this say which is better?
No. It says who uses what, by company size, industry and country, so you can see which tools companies like yours choose. For features and prices, read the vendors.
Can I get the companies on any of these?
Yes: click the tool, see the first 20 companies, and sign up for the full list with verified e-mails. Counting is free.
Get these companies 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 POSIX
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