From Valve Developer Community
... 
Important:This page uses the {{lang}} translation
template, which is deprecated.
It should be replaced by the
{{MultiPage}} template if possible.
For more information, see this page.
Stub
This article or section is a stub. You can help by adding to it.
Rubikon is Valve's custom physics engine used in Source 2. It replaces Havok, which is the main provider of physics for Source engine games.
Media