Mac OS X was a series of graphical operating systems developed and marketed by Apple for its Macintosh line of computers. It succeeded the "classic" Mac OS (which dates back to the launch of the original Macintosh in 1984) and NeXTSTEP (which was developed at NeXT after Steve Jobs left Apple). It has since been superseded by macOS, starting with macOS 10.12 "Sierra" in 2016. 
Native PDF support
Mac OS X used a PDF-based imaging model called Quartz. This replaced NeXTSTEP's Display PostScript implementation to avoid royalty fees to Adobe Systems. However, as Mac OS X's use of PDF prioritizes speed and compatibility over features and compression, it is limited to PDF 1.3 (or PDF 1.4 for document "bundles" which contain embedded graphics). Newer PDF files will either display incorrectly or cause a performance hit as Mac OS X will internally downconvert the document for display.
|Mac OS X version||Code name||Release date||Note|
|Mac OS X Server 1.0||Rhapsody||1999-03-16|
|Mac OS X Public Beta||Kodiak||2000-09-13|
|10.4 "Tiger"||Merlot||2005-10-29||Last to support classic Mac OS apps, and first to support Intel processors.|
|10.5 "Leopard"||Chablis||2007-10-26||First version to fully support 64-bit apps (CS4 and later).|
|10.6 "Snow Leopard"||2009-08-28||Last version to support PowerPC apps (CS2 and earlier).|
|10.7 "Lion"||Barolo||2011-07-20||Required for first Creative Cloud app. Java no longer included by default.|
|10.8 "Mountain Lion"||Zinfandel||2012-07-25|
|10.9 "Mavericks"||Cabernet||2013-10-22||Issues with Premiere Pro CS3.|
|10.11 "El Capitan"||Gala||2015-09-30|
|macOS version||Code name||Release date||Note|
|10.13 "High Sierra"||Lobo||2017-09-25||Issues with InDesign CS3, Photoshop CC 2015 and earlier.|
|10.14 "Mojave"||Liberty||2018-09-24||Last to support 32-bit apps (CS3). Security adjustments may be required.|
|10.15 "Catalina"||Jazz||2019-10-07||No longer supports 32-bit apps.|
|11.0 "Big Sur"||GoldenGate||2020-11-12||Begins transition from 64-bit Intel to Apple processors.|
- NeXT: Apple’s Right Choice by Jonathan Ploudre, Low End Mac. 2001-05-07.
- macOS and OS X version code-names by Rene Ritchie, iMore. 2018-08-15.
- Mac OS X and PDF by Laurens Leurs, Prepressure. 2013-08-09.
- Why does Preview save as PDF version 1.3 instead of version 1.7 sometimes? by Lance000, Apple Communities. 2013-12-04.
- Graphics & Imaging Overview, Apple Developer Connection. 2004-09-08. Archived 2004-09-17.
- Speed up PDF viewing in Preview, Macworld | Mac OS X Hints. 2009-03-17.
- cc in snow leopard by Brucgovn, Adobe Support Community. 2015-06-29.
- Install Java (JRE) | Mac OS 10.7 and later, Adobe Inc. 2017-08-30.
- ADOBE PREMIERE PRO CS3 Problems - RED SCREEN Overlaps Sequence Timeline by Jay Van, Creative Cow. 2015-02-19.
- Does ID CS3 work with High Sierra? by williamdesign1, Adobe. 2017-10-19.
- Photoshop and High Sierra | macOS 10.13, Adobe. 2019-08-22.
- If any of your apps don't work in MacOS Mojave, a small tweak in your settings might fix the problem by Dave Smith, Business Insider. 2018-12-06.
- macOS at Apple
- Installing Creative Suite on macOS 10.12 (Sierra), macOS 10.13 (High Sierra), and macOS 10.14 (Mojave) at Adobe (2020-04-23)
- An Illustrated History of macOS at Git Tower
- A Summary of the Different Version of Mac OS X at PowerMax
- Mac OS X & macOS version code-names at MacWorld
- Mac OS X and PDF: The Real Story (PDF) by Leonard Rosenthol at Planet PDF (2001)
- Mac OS X at the Apple Wiki
- Mac OS X at the Macromedia Wiki
- macOS: Release history at Wikipedia