"Valve and Sony" are apples and oranges. Valve hasn't been a publisher (in the usual sense) or a platform creator until very recently. They've been a retailer and a developer. As a retailer, Valve has an incentive to grow the industry as a whole, and as a developer, they have an incentive to get people onto platforms that are easy for them to develop and sell products for.
They've chosen to tackle these interests by deliberately doing things "wrong" right from the beginning. SteamOS/Steambox is all about having an open, accessible platform, and the release of development tools is all about getting people to develop for this platform so that users will adopt it.
Unity isn't exactly "open," it's actually closed source which can be a big pain if something goes wrong. Compared to traditional game development where usually you have access to all the source it is a big pain (for me at least).
All of them? It's unheard of at a AAA development level to sell an engine without full source access; CryENGINE, Unreal, iD Tech, and Gamebryo all offer full source licenses, to name a few examples.
Any 3rd party engine used by a AAA game will have full source. Unreal Engine, Crytek, Source, etc. Sometimes those engines have cheap, no-source indie targeted licenses but the high end games paying the high price tag has source.
Hopefully they'll use it to make Dota 2 for Linux comparable to Dota 2 for Windows :)
Right now it doesn't perform well at all (using 2x more memory and being significantly slower on Intel GPUs) , and still comes with an annoying sound bug (https://github.com/ValveSoftware/Dota-2/issues/770)
It may be related to Intel's drivers, as I am playing Team Fortress 2 on Linux, which is I believe native OpenGL, and it is significantly slower than on Windows with an intel GPU.
This replaces the opengl dynamic library, similar to apitrace. It should work for any opengl app (the example they use is a simple gl app that draws some spheres). When the app makes an opengl call, it logs it to tmp before forwarding it on to the real opengl library. It's kind of like strace for graphics...
Then, there are tools to analyze and inspect those logs. You can presumably replay a frame, and step through each GL call and inspect the data it is sending. I haven't tried building this yet, but it looks like it includes a tool to replay the GL calls, and some kind of interactive GUI.
I have been checking the code for the generation of the spheres. I never developed C++ professionally. Is this code considered good C++ practice? I mean I saw "using namespace std", and exceptions using cout.
If it's just a simple demo app, I probably wouldn't use it as a example of good C++ practice.
Many C++ devs have a different idea on what idiomatic C++ should look like. C++11 really shakes things up as well.
There's no reason a "using namespace std;" is bad, as long as it isn't in the header. If it's in the header file, every file that includes that header will have it's namespace polluted with std declarations, and this leads to a big nasty chain of potential name conflicts (one header file includes another and so on and so forth).
Historically the state of OpenGL debugging and profiling tool is quite a mess unfortunately, especially on OSX and Linux. D3D always came with a matching PIX for capture-analysis (capture frames and step through them), and NVIDIA's PerfHUD for live-analysis (analyse the running game with a realtime overlay). For OpenGL there was gDebugger which was commercial, then free, and hasn't been updated in years and probably is stuck to an old GL version. Then there's NVIDIA Nsight which seems to be limited to NVIDIA GPUs (but has a very nice VisualStudio integration). Apple only seems to care about GLES on iOS, not desktop GL. So VOGL could really fill a gap.
Valve need to encourage game devs from a console and windows centric world to develop for the SteamEngine platform. PIX (http://en.wikipedia.org/wiki/PIX_%28Microsoft%29) is one of the tools these developers are used to dealing with. So having a Linux equivalent is pretty valuable.
It can capture all OpenGL drawing commands made by an application and then replay it frame by frame. Valve devs gave a presentation about it including a demo. http://www.youtube.com/watch?v=45O7WTc6k2Y The part about vogl starts at around 33 minutes and the demo at 40 minutes.