macOS Sequoia is certified to Unix 03

I’ve always thought POSIX compliance is the primary thing vendors should be targeting for portability. I was trying to find something that would explain the difference between POSIX and UNIX compliance, but there’s not great sources on this specifically.<p>I imagine UNIX is a superset of POSIX, I’d be curious if anyone knows of a simple comparison between the two?

It may be &quot;certified&quot; but that hardly matters when MacOS Sequoia is a pay-to-access-networking operating system. <a href="https:&#x2F;&#x2F;developer.apple.com&#x2F;forums&#x2F;thread&#x2F;663875" rel="nofollow">https:&#x2F;&#x2F;developer.apple.com&#x2F;forums&#x2F;thread&#x2F;663875</a> <a href="https:&#x2F;&#x2F;developer.apple.com&#x2F;documentation&#x2F;bundleresources&#x2F;entitlements&#x2F;com_apple_developer_networking_multicast" rel="nofollow">https:&#x2F;&#x2F;developer.apple.com&#x2F;documentation&#x2F;bundleresources&#x2F;en...</a><p>It&#x27;s absolutely wild. They&#x27;ve broken multicast and UDP for all applications that do not pay Apple money (like open source, community coded ones). Which means things like mouse&#x2F;keyboard sharing applications like synergy&#x2F;barrier&#x2F;etc stopped working in many cases. But that&#x27;s just the tip of the iceberg. And there&#x27;s no way for a human to control this &quot;multicast entitlement&quot; on their own OS how they like it. The only way for applications on Sequoia to have multicast network access is for some commercial developer pay for it.<p>This is very not Unix. Careful out there &quot;up&quot;grading.

I remember a time when this mattered in terms of branding (Mac OS X being a Unix). It meant that the OS was “industrial-class”. This was against a backdrop of Macs not being seen as serious machines, unlike Windows machines which were more “corporate”.<p>But nowadays macOS is so pervasive that a Unix certification doesn’t buy much brand cachet. Perhaps it might help for specific compliance requirements but those are likely the minority.

I’ve always wondered, since back when OS X 10.5 got apples first Unix certification.<p>What does that help you as a developer? Can you just download the spec for free, built against it and have a working app for several platforms that not only compiles and runs but also behaves the same on all of them?

Relevant post &#x2F; discussion <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=29984016">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=29984016</a>

Are there any other operating systems today that are Unix certified?

... with some GNU components stuck in 2006.

I love how Apple basically cp -R BSD, became the most profitable company in the world off it and gave nothing back except a walled garden and lock in. But hey it’s still technically Unix.