Patryn of Elvenshae said:
Kukris are now martial weapons.
Yup. They were exotic in 3E because they were a size category smaller than a shortsword (Tiny instead of Small), but had a better crit modifier than a Tiny shortsword - they were thus 'better than Martial'.
In 3.5, they're the same size category as a shortsword - they're both Light weapons. The shortsword is 1d6 19-20x2, and the kukri is 1d4 18-20x2, which are effectively equivalent. So they're both Martial.
The off-hand end of a double-weapon counts as a light weapon in terms of two-weapon fighting penalties. No more, no less.
And for Power Attack, per the Feat description.
Note that that means that by strictly adhering to that, the primary end of the double weapon gets 1.5x Str bonus to damage (since it's a two-handed weapon, and nothing about the penalties associated with two-weapon fighting changes that), and both ends get +4 to Disarm checks (like any other two-handed weapon).
My personal inclination is to treat it as a combination of one-handed and light weapon for all purposes... so 1x/.5x Str bonus to damage, and +0/-4 for Disarm checks... and off-end finessable.
After all, the Power Attack feat text states "Normally, you treat a double weapon as a one-handed weapon and a light weapon. If you choose to use a double weapon like a two-handed weapon, attacking with only one end of it in a round, you treat it as a two-handed weapon." It doesn't limit it to only TWF penalties - just says "normally it's one-handed and light".
-Hyp.