This tool is what I use to identify extensions etc:
http://realtech-vr.com/admin/glviewNote that there is an exception specific to the Intel HD3000 on Windows 10. It may report OpenGL 3.2 support, but Intels OpenGL driver on those GPUs is actually broken on Windows 10 and doesn't work reliably (because the driver is designed for Windows 8 only).
Short of those Sandy Bridge Intel GPUs on Windows 10 (and any earlier Intel GPUs for that matter), OpenGL 2.1/3.2 support is actually quite widespread. Any graphics card from the last 10 years or sometimes even more will support it.
Only Intel disappoints by not having a Windows 10 driver for Sandy Bridge, even though the hardware can do OpenGL just fine.
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For performance questions:
The drawing quality options Jim mentioned don't actually do anything for OpenGL, they're a hold-over from D3D Theater View and I'll probably hide them when OpenGL is active. There is one quality knob that I can re-introduce, and that is controlling anti-aliasing. OpenGL always renders against the VSYNC, which means that the Framerate option is also not supported.
There is always more things to be done to improve performance, too.