Havok

Havok is an Irish computer software company that works in partnership with many game developers, including Microsoft, Nintendo, and. The company is well-known for its physics engine in particular, which has been in active development since 2000. Havok's technology has been used in more than 150 games, including Super Smash Bros. Brawl and Super Smash Bros. 4. The company was a subsidiary of American computer company from September 14, 2007 until October 2, 2015, when Intel sold Havok to Microsoft for an undisclosed amount.

In Super Smash Bros. Brawl
The Havok Physics engine was used during development of Brawl.

In Super Smash Bros. 4
The Havok Physics engine was again used during development of Smash 4.