If you are a phaser dev then reference the phaser.d.ts in your project.
phaser.d.tscontains a reference topixi.d.tsand so both these files must remain siblings in the same directory.pixi.d.tshas no dependencies and can be used by pixi devs standalone*
*Versions of TypeScript lower than version 1.0 may experience errors in pixi.d.ts due to missing WebGL definitions. If you fall into this category and cannot upgrade your version, then a webgl.d.ts has been provided but is disabled by default. Add this line to the top of the pixi.d.ts file /// <reference path="webgl.d.ts" />
If you find any mistakes in these definitions or you feel they can be improved in any way, please make a pull request against the dev branch.