As the opposite of the "great Linux/open-source achievements of 2015" that I'll be detailing in another article, here's the items I've been thinking about for the past few days that didn't become reality this calendar year or were just a disappointment:
Many were looking forward to the Vulkan specification being published by year's end along with the initial reference drivers. Sadly, this Khronos specification didn't make it for this year. From what I heard on the state of Vulkan, it could be a few months into 2016 before they go public due to waiting on a conforming implementation.
Most Steam Linux Games Are Still NVIDIA-Only
This is due to a variety of factors, but most major Steam Linux game releases continued to only be advertised as working with the NVIDIA Linux driver. This is in part due to the Mesa/Gallium3D drivers not supporting all of the OpenGL 4 extensions for some games, poor performance out of the open-source drivers and AMD Catalyst, and other factors, but hopefully this macro issue will see improvements in 2016. Ideally, hopefully more game studios will turn to better QA and testing for Linux. It would also be ideal to see more of these Linux game porting studios work with the Mesa developers, or at least allow them early-access testing to new Linux games or free access once released. Some studios have been working with Intel on their driver, but there doesn't seem to be much that way for Nouveau and Radeon. For some games it has taken months before they begin running nicely with the proprietary AMD driver.
No Magical Catalyst / Radeon Software Breakthrough
Sadly there was no Christmas miracle for improving the proprietary AMD Linux graphics driver... Related to the previous disappointment, the Catalyst driver (now known as "Radeon Software") really isn't cutting it for most Linux gamers. There was no big release to really overhaul their OpenGL support. In 2016 hopefully the situation will get better though with the new unified approach and in making use of the AMDGPU kernel driver and isolating Catalyst to be a user-space blob.
It was talked up before that in 2015 the initial Ubuntu Phone converged experience would become a reality and that even at least one Ubuntu Phone with convergence support would be available. Sadly, that's not quite ready yet and the first device is delayed to 2016. Ubuntu Phone though at least made much progress this year and developers continue working towards the convergence vision.
NVIDIA Firmware & Nouveau Re-Clocking
It's been more than one year since the GeForce GTX 900 series and sadly there still isn't any signed NVIDIA firmware images for allowing the open-source Nouveau driver to support hardware acceleration. The GTX 900 series were called very open-source unfriendly hardware. It sounds like though NVIDIA will hopefully soon release signed firmware images, considering it's been more than one year after all, so that the open-source support can finally move on... On a similar note, Nouveau Kepler re-clocking has made progress this year, but there still is much work ahead. Nouveau is largely community driven and those guys are doing their best, but sadly NVIDIA hasn't stepped up their open-source game this year.
OpenGL 4 For Intel
Thanks to landing tessellation support this week, the Intel Mesa driver is very close to reaching OpenGL 4.0 compliance and just a few away from OpenGL 4.2 support. However, for 2015, they didn't make it and their Mesa driver only meets OpenGL 3.3 compliance. While they are close with GL4, the pre-Broadwell graphics hardware will still take longer before being compatible with all of the extensions.
No Btrfs Surprises
While there's always talk of Btrfs as being the next-generation Linux file-system and it being the future, 2015 wasn't the year of Btrfs. Outside of SUSE/OpenSUSE and some smaller distributions, most distributions continue relying upon EXT4 by default and there are no indications the Btrfs will command the Linux file-system experience anytime soon.
Work continues to go on with POCL, Gallium3D Clover, Intel Beignet, and other projects implementing open-source OpenCL drivers. The Gallium3D OpenCL stack is still battling with OpenCL 1.2, Beignet is still working towards OpenCL 2.0, and really there hasn't been any upward direction on OpenCL use by the open-source Linux desktop. There also continues to be ongoing work with open-source AMD HSA support. Distributions like Ubuntu still aren't even shipping with these components by default. It can be looked at as somewhat of a "chicken and the egg" problem, but simply put, the open-source OpenCL ecosystem doesn't seem too vibrant at the moment. Aside from LibreOffice and GIMP 2.9, it's hard to think of many day-to-day Linux desktop programs really looking toward this GPGPU specification.
Linux Gaming Market-Share Didn't Grow Much
There were many Linux games released this year, continued work on the graphics stack, big improvements to SteamOS, and Steam Machines are now shipping, but the Linux gaming market-share is incredibly tiny compared to Windows and still smaller than OS X. Steam's monthly surveys continue showing about a 1% market-share for Linux gaming.
Skylake Graphics Support
It took until after Intel Skylake hardware was already shipping before the open-source graphics support was stabilized. It was with Linux 4.3 that shipped after the Skylake launch that the graphics support was no longer marked as experimental and when the Skylake audio support landed. Ubuntu 15.10 and Fedora 22 have less than ideal support for these latest-generation processors. It's still better than the fudged Linux support at Sandy Bridge's launch, but less than ideal compared to where the out-of-the-box support was for Ivy Bridge and Haswell.
It's taken most of the year and still somewhat ongoing for projects to provide good HiDPI support for high resolution displays (4K, etc).
Those are all of the major items that came to my mind. Is there anything I'm missing? If there was any vaporware this year you cared about or Linux/open-source announcements/releases that made you sad, feel free to share by commenting on this article in our forums. Coming up next will be some of the best Linux/open-source accomplishments of 2015.