Costs and requirements to support OSX

I have a couple of general questions about developing for OSX and would be grateful for some practical advice. Developing engineering software mainly using "unixy" cross platform software and tools. Linux and Windows are supported and the pros and cons of supporting OSX is being considered.

Is there a developers program that gives access to OSX versions for the last 10 years or so?

I am aware there are licensing issues concerning OSX and virtualization. How do software developers tend to go about testing their software over a range of OSX versions (as well as a range of Windows and Linux versions)?

Like iOS, OS X has a very high adoption rate when a new version is released. The majority of PowerPC based Mac owners are running OS X Leopard, virtually all pre-2007/2008 Intel Mac users are running OS X Snow Leopard and a large portion of newer Mac's are running either OS X Lion or Mountain Lion..

So testing with versions prior to OS X Leopard depends on how much money your apps costs. I.e., if you're selling an app for $1000 per copy, then you want to test on ALL versions of OS X to ensure you don't leave any money on the table. If you're app costs $19.99, you want to get OS X Leopard on ward. If your app costs $0.99, then you might want to go OS X Snow Leopard onward..

While the Developer access on Apple might get your access to all of the previous SDKs, you don't get the actual OS itself..and getting your hands on the installation discs of those versions and the Macs to run them is not cheap..

To be able to bring Windows and Linux into the fold, you need to look at cross-platform frameworks. The native OS X framework only targets OS X just like Win32/MFC target Windows only..

You can look at frameworks like Qt that work on OS X, Linux and Windows. Mono is another option to bring C#/.NET apps to OS X and Linux..

Not sure what you mean about licensing issues with OS X and virtualization?

Those cross-platform frameworks may also have limits on what versions of each respective operating system are supported. Mono requires at least Leopard (10.5) for example. Any other libraries linked to as well might have to be recompiled for different versions of OS X (assuming they work at all).

Thanks for the responses but I think I should clarify things a bit. The engineering software is low volume and high cost. It is largely written and runs on Linux, Windows and with minor tweaks would run on OSX. An older version used to run on OSX 10.3. In order to properly test and support the software it is necessary to be able to run on all the versions of the operating system clients would encounter, say, all the major versions in the last 5-10 years in all the supported languages. Typically this would be done using virtualization and typically the companies selling operating systems would provide mechanisms for software to be supported on earlier versions of their products.

OSX is not a widely used platform for engineering. I used it (along with Windows and Linux) for about 5 years and during this time it became clear that Apple was a bit odd when it came to technical support. For example, when looking to purchase a computational cluster they denied having any internal technical support and directed me to an independent consultancy for benchmarking. I tried to post this question on the developers forum, perhaps I misunderstood, but they seemed to want $99 to allow their users to answer questions for them. I have also tried to ask at one of their shops without success.

Concerning the license and virtualization, which is supposed to have improved recently!, for OSX 10.8 bought from the App store:

“(iii) to install, use and run up to two (2) additional copies or instances of the Apple Software
within virtual operating system environments on each Mac Computer you own or control that is
already running the Apple Software, for purposes of: (a) software development; (b) testing
during software development; (c) using OS X Server; or (d) personal, non-commercial use.”

So how do companies go about supporting their software on OSX? Do they purchase licenses from Apple and not the App store? If so, what is the programme called?

Only recent versions of OS X can be virtualized (I believe that policy started with 10.7). As such, if you need to run older versions, you'll need to have physical machines.

As for your questions, I can't say for sure since I'm not a professional developer but I can offer some advice. First, as I noted, if you need to test the software on multiple versions of the OS, you'll need to secure older machines, especially since Apple switched architectures between releases (PPC -> x86). Second, if you can't get the discs with the machine, you'll need to find physical copies of OS X before Lion since Lion (10.7) was the first version to be released on the App Store. That said, even Lion is no longer offered on the App Store so your best bet there is to find a machine that has it installed.

On Monday morning I found an Apple consultancy/reseller and asked an experienced support engineer/developer about support programmes, older operating systems, and such. It would seem there is effectively no support from Apple beyond a modest amount for the previous version of the operating system. The way to support current software on older versions of OSX looks like, as suggested above, buying old hardware and old OS discs from ebay. Even this can be problematic since, for example, there is no way to get Apple products like Safari on the older versions of OSX to support current web standards. His view was that this has arisen for commercial reasons.

Thanks for the input and it looks like supporting long lived software on OSX is going to be more awkward and expensive than other platforms.

Yes, Apple has a tendency to move on quickly from older versions of software relative to, let's say, Microsoft. Part of this has to do with release cycles. Take for instance the period between Windows XP and Vista. XP was released in Oct. of 2001 and Vista in Jan. of 2007. During that same period, Apple released three versions of OS X (and one was released a month before XP). Although MS has gotten much better at accelerating their release schedule, Apple has been doing it for a much longer period and this gets reflected in the type (lack) of support they provide for what seems like "newish" versions.

vansmith said:

Yes, Apple has a tendency to move on quickly from older versions of software relative to, let's say, Microsoft. Part of this has to do with release cycles. Take for instance the period between Windows XP and Vista. XP was released in Oct. of 2001 and Vista in Jan. of 2007. During that same period, Apple released three versions of OS X (and one was released a month before XP). Although MS has gotten much better at accelerating their release schedule, Apple has been doing it for a much longer period and this gets reflected in the type (lack) of support they provide for what seems like "newish" versions.

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It is interesting that we seem to have rather different views on the pros and cons of new operating systems. I had an Apple computer during this period and used Framemaker for writing documents. Two weeks after I bought Framemaker for Mac Adobe cancelled the long delayed OSX version citing, among other things, costs of maintaining software across upgrades which broke working programs. This annoyed me at the time but I see from wikipedia Apple also suffered for their approach:

"Adobe Systems acquired the product and returned the focus to the professional market. Today, Adobe FrameMaker is still a widely-used publication tool for technical writers, although no version has been released for the Mac OS X operating system, limiting use of the product (FrameMaker up to version 7.0 ran under Mac OS 9, and is usable under Mac OS X, through version 10.4.11 "Tiger", on PowerPC-based Macs in the Classic emulation environment, but there is no Mac OS X native version of FrameMaker). Note that latest versions of Mac OS X, v10.5 "Leopard" and newer, eliminated Classic support, even for PowerPC-based Macs. Therefore, if running Mac OS X 10.5.x, it is now impossible to run any Mac version of FrameMaker using Apple-supplied software. An alternative is SheepShaver, a GPL-licensed, open source MacOS Classic run-time environment available for both PowerPC and Intel Macs. The decision to cancel FrameMaker caused considerable friction between Adobe and Mac users, including Apple itself, which relied on it for creating documentation. As late as 2008, Apple manuals for OS X Leopard[3] and the iPhone[4] were still being developed on FrameMaker 7 in Classic mode; Apple has since switched to using InDesign."

The institute I was at at the time installed Windows XP on all the new Vista equipped computers they purchased. I think it may have continued until Windows 7 came out. They did this because it was far more important that working hardware and software continued to work compared to whatever benefits Vista may have had over XP.as an operating system.