The Microsoft sculpt:
<a href="https://www.microsoft.com/accessories/en-us/products/keyboards/sculpt-ergonomic-desktop/l5v-00001" rel="nofollow">https://www.microsoft.com/accessories/en-us/products/keyboar...</a><p>It's had good Linux support for a while now.
An older <a href="http://www.goldtouch.com/ergonomic-keyboards/" rel="nofollow">http://www.goldtouch.com/ergonomic-keyboards/</a>, might even be version 1.