There are many web applications where you can create slides and presentations without using Powerpoint in Windows, but nothing will provide you with syntax highlighting and Math formula features. The one that provide this feature is Slideship.
Slideship provides easy way to create slides and presentations. It uses markdown feature to highlight the code for different programming languages. You just need to focus on your contents, no need to adjust font-style, size and margin. It is that simple. You can also add math formulas using TeX format like the picture below.
Just watch this video below you will understand how easily you can create/add and share slides using Slideship. It is still in development so you can see more features added in future.