Usually for me I can get a game working with POL and very few tweaks. Sometimes though I can ask the creators of the game for a Linux version and they are nice enough to give me a Linux copy of the game.


Cool game developers that have given me a Linux version:
-Tiger Style Games(Waking Mars)
-Zachtronic Industries(SpaceChem)

Game developers that flat out rejected me, and coincidentally offer poor customer service to boot:
-Runic Games(Torchlight)

Be clear, the gaming companies don't have to do these things, but the ones that go that extra mile with customer service find that I continue to support and give good word about their games, the ones that don't I spread the news of the bad service.

If the Humble Bundle sales are to be believed, the Mac gaming market is roughly the same size as the Linux gaming market, yet they support Mac.

Not at this point .
Not sure that would strictly be correct . I get the odd feeling Linux gamers grab anything and everything when there are linux games on sale, and they come out of the woodwork then - ie they seem to have more cash to splash if average prices paid say when u look at sales of IGS games - they seem to pay higher on average than both mac and pc gamers :P
Mac gaming has arguably been around a lot longer (if not longer, more mature.... which isnt saying much - come on this is gaming on a Mac .....

Wait a minute until I have my crystal ball out...

The Mac OS runs on many more computers than the Linux OS. Approximately 3-4 times as much. The Humble Bundle sales might be an exception but I guess that indeed you can expect a bit more sales from Mac than from Linux. And even around Mac games on GOG it got quite quiet lately. Probably they don't sell much here.

http://en.wikipedia.org/wiki/Usage_share_of_operating_systems

Indeed, but the proportion of Mac users that game on their Macs is much lower than on Windows or Linux.

The majority of Mac users don't even see their computer as a gaming device, and pretty much every Mac owner I know uses Boot Camp with Windows to run games, as the games tend to (a) be cheaper and (b) run better (unless they're available on Steam as well, in which case (b) applies).

I would imagine there are more DRM free... enthusiasts... using Linux than Mac, so they might more enthusiastically support the humble bundle.

Which actually means they would support GOG well.

I imagine if they did support Linux, it would just be Ubuntu, it would be totally unfeasible and unprofitable to juggle management of multiple builds and patching for multiple distros

If you take a look here http://cheesetalks.twolofbees.com/humble/ on the purchase numbers (and not payment) the percentages are for HIB8:

Windows 81.4%
MacOS 11.9%
Linux 6.3%

MacOS has approx. the double marketshare of linux, according to last HIB and is reasonable to support as this 11.9% form a addressable platform.

For linux this 6.3% are fragmented further to even more insignificant fractions (http://constantmayhem.com/ty-stuff/linuxsurvey/2013.html):
Ubuntu 1.7%
Arch 1.27%
Mint 0.69%
Debian 0.54%
Fedora 0.43%
Xubuntu 0.31%
Gentoo 0.21%
Kubuntu 0.20%
Crunchbang 0.15%
OpenSuse 0.11%
Other 0.71%

The fragmentation ends not here, for instance Ubuntu is fragmented further into these incompatible OSs' (% from Steam HWsurvey http://store.steampowered.com/hwsurvey/?platform):
Ubuntu 12.04.2 LTS 0.21% (12.6%)
Ubuntu 12.04.2 LTS 64 bit 0.39% (23%)
Ubuntu 13.04 0.253% (14.9%)
Ubuntu 13.04 64 bit 0.83% (49%)

I wonder what the meaning of incompatible OS is in this context? Supposedly it's about providing a unified installation or about games compatibility. I would guess that Ubuntu 12.04 and 13.04 shouldn't show that any significant differences there and should be regarded as compatible OSs.

Kernel version differs and also glibc version, which might produce problems on binary distributed software outside of a repositories (http://stackoverflow.com/questions/2856438/how-can-i-link-to-a-specific-glibc-version?lq=1)
Along with several other libraries... so stuff might break (http://ubuntuforums.org/showthread.php?t=2157427 https://bugs.launchpad.net/ubuntu/+bug/1210693 http://digitalvomit.blogspot.de/2013/05/upgrading-to-kubuntu-1304-from-1210.html)

Also, as kernel version was changed hardware might work "different" as drivers were updated (better or worse e.g. https://bugs.launchpad.net/ubuntu/+bug/1173759)

Ubuntu release__ Kernel___________version glibc
12.04 LTS_______3.2.12____________ 2.15
12.04.1 LTS _____3.2.12
12.04.2 LTS _____3.5
12.10 __________3.5
13.04 __________3.8______________ 2.17

In short, Ubunutu has repositiories per release, which shows clearly that they are incompatible, they needs to be built and supported individually.

Normally games shouldn't mess with the kernel, nor with the drivers. As for libraries, you can install older versions in parallel with new versions. That's why linux has library versioning... which is still missing in windows if I'm right.

games mess heavily wiht drivers, e.g. graphic card drivers and their capabilities.

Library versioning is a workaround for missing stable APIs and the capability of using-per-app local libraries.

Also, it works not with all libs e.g. glibc. Built a game against a newer glibc will result in non-runnability on older systems, it's a problem (upgrading your system might break your system: https://bugs.launchpad.net/ubuntu/+source/software-center/+bug/578045).

Under windows, If you build your game against the newest directx 9c SDK build 2010 it will work fine with a win98se with a dirextX 9c from 2002, it's great for ISVs and binary software deployment.

Most games I've seen use OpenGL, which is backwards compatible for the most part. OpenGL then handles the communication with the drivers, and it's also the layer that should solve any compatibility problems. I imagine there are similar libraries for input and audio.

That was a -lot- of really interesting information you've linked there, thanks. At any rate, using Wine as the middleman sounds like a fairly reasonable idea.