Haxe is a programming language that can be transpiled to many other languages thanks to the powerful Haxe compiler. Because of this very nature, Haxe is really versatile and the Haxe developer spectrum is really wide. Developers use Haxe to develop games, web apps, mobile apps, desktop apps, servers, tools, etc. Therefore, when authoring a Haxe library, ideally it should cover as many targets as possible. So that everyone would be able to use it. Here I would like to list a few approaches to utilize Haxe and its targets to write truly cross-target code, using a work-in-progress Big Integer library I have been working on recently.