Ive got it running on a slice of bread here - looks great!

This renders fine on my Linux machine with integrated graphics (chromium).

An occasional hanging frame, but nothing serious.

Huh. It's running perfectly fine on my 2009-era thinkpad x201 (i5 with Intel integrated graphics...) Are you using the Intel driver, with mesa-libgl?

I'm viewing it in Firefox on Arch linux.

It rendered smoothly for me on a macbook pro running MacOS 10.11, iPhone 6Plus with iOS 9, A Virtual Box running Kali Linux, and a Virtual Box running windows 10. I'd say the issue is with you machine/setup.

I think you have a driver problem. Absolutely fine here on Linux Mint with intel integrated graphics.

Rendered just fine for me.

Linux machine with i5-2450M CPU @ 2.50GHz and i915 integrated graphics, running Chrome.

If it's as slow as you say, it sounds like you're getting software rendering.

I can confirm that the machine from 2008 with the Intel Integrated Graphics 965 really doesn't work. This stuff obviously needs the newer technology. If your machine is more recent, then the problem could be the drivers.

Must be a driver issue or very, very old Intel graphics. It works fine on Chrome/Android, and usually my Intel HD4000 on Linux/Chrome renders WebGL many times quicker than this phone...

For what it's worth, it's working pretty smoothly on my Nexus 5. Maybe it depends on some hardware acceleration that only newer (but not necessarily high-end) GPUs have

Huh. I'm running it on a Linux machine with a Core i5 (Intel(R) Core(TM) i5-4210M CPU @ 2.60GHz according to /proc/cpuinfo), and it's a bit CPU-intensive (it makes my laptop's fan kick into gear) but it's smooth and responsive and everything obviously works the way it's supposed to. Doesn't even come close to eating a gig of RAM, out of the eight I have.

Firefox 41.0.2 on Ubuntu Vivid Vervet (3.19.0-31-generic), on a LinuxCertified.com LC2430E. (Good laptop. No Microsoft tax. Yes, that is a blatant plug. So's this WebGL demo.)

Rendered perfect for me. 2009 HP computer here.

2007 Thinkpad X61T here (Intel GMA 950, Core2Duo 1.6 GHz) running Linux Mint. Works about 5-8 fps (at SXGA+ resolution no less), fast enough to be enjoyable.

I reckon this is quite RAM-intensive, at least a few hundred megabytes, which might be leading to problems for some people.