Cool tech, but I'm a bit sad that I can't watch Shumway[1] using Shumway.
If you use Shumway, though, don't forget to disable Adobe's Flash (I've found that having it enabled and Shumway installed results in rather brutal crashes).
0) Have a Macbook Air running OS X Yosemite
1) Install Firefox
2) Install Adobe Flash
3) Install Nightly
4) Install Shumway
5) Attempt to open http://www.albinoblacksheep.com/flash/shumway
6) Watch Firefox complain that the tab crashed
7) Try to reload the tab
8) GOTO 6
Disabling Flash (via the Addons screen in Firefox/Nightly) seems to fix the issue.