OpenGL is deprecated

http://www.anandtech.com/show/9038/next-generation-opengl-becomes-vulkan-additional-details-released

SPIR-V is a new spec developed in tandem with Vulkan. It's an update to SPIR 2.0, which was finalized last August.

SPIR has previously been Khronos' intermediate language for compute shaders, used for harnessing the GPU's power for non-graphical workloads using the OpenCL API. It's analogous to the Direct3D shader bytecode, but for compute tasks rather than graphics ones. It's useful for similar reasons, too. OpenCL supports developing these programs using a C-like language, but this is complex for OpenCL drivers, as it means that they must support compilation of that C-like language. Further, many developers do not want to use C.

SPIR provides a solution. Compilers can emit SPIR intermediate code, and drivers can process that directly. This avoids both the complexity of supporting the C-like language, and it gives developers much more flexibility: there are, among others, JavaScript, C++, Python, Java, and Haskell-based languages for writing these GPU compute programs, with the compilers producing SPIR code.

SPIR-V unifies graphics and computation. Both OpenCL 2.1, also announced today, and Vulkan will ingest programs in SPIR-V intermediate code. These could be graphical shader programs originally written in GLSL, they could be computational shader programs originally written in OpenCL C, or they could use alternative development languages; they'll all be compiled to SPIR-V. As such, display drivers will only need to handle one shader language.
http://arstechnica.com/gadgets/2015/03/khronos-unveils-vulkan-opengl-built-for-modern-systems/

The next generation graphics API from Khronos.
Vulkan is the new generation, open standard API for high-efficiency access to graphics and compute on modern GPUs. This ground-up design, previously referred to as the Next Generation OpenGL Initiative, provides applications direct control over GPU acceleration for maximized performance and predictability.
“Industry standard APIs like Vulkan are a critical part of enabling developers to bring the best possible experience to customers on multiple platforms. Valve and the other Khronos members are working hard to ensure that this high-performance graphics interface is made available as widely as possible and we view it as a critical component of SteamOS and future Valve games.”
Gabe Newell - Valve

Direct control over GPU operation, with minimized driver overhead for maximum performance
Multi-threading-friendly architecture to increase overall system performance
Designed to be used in a wide variety of devices including mobile, desktop, consoles, and embedded platforms

Uses Khronos’ new SPIR-V™ intermediate representation for shading language flexibility and simplified drivers (see more on SPIR-V here)
Extensible layered architecture enables innovative tools without impacting production performance while validating, debugging, and profiling
Simpler drivers for low-overhead efficiency and cross vendor portability

glBegin and glEnd is all you should need.

>>4
But that's deprecated onii-san~

The biggest question in my mind is whether the major implementers will opt to use SPIR as an intermediate format for their existing GL implementations. Given how slow nVidia and Intel have been in evolving their driver stacks I suspect the answer to that question will be "no", even if Vulkan itself sees wide adoption.

Also, I'm sure the GL compiler people will be swift to come forward with the usual we-want-a-structured-representation-because-reconstructing-dataflow-from-bytecode-is-hard. From what little I've read that argument seems to carry more weight with folks who are targeting in-order hardware like GPUs.