Features i estimate as essential for this app :
| Browser \ Func | SVG DND | Replace default keyboard shortcuts | Unload events | |
| Used for | Drag'n'drop cards between zones | Ctrl+D for draw, Ctrl+U for untap, etc. | Detecting closure of cards list, detecting a user quit | |
| Firefox | yes | yes | yes | |
|---|---|---|---|---|
| Opera | no | no | no | |
| Chromium | no | no | yes | |
| IE | No support for SVG | |||