You should now have a basic understanding of the basics of WebGL. But to do anything useful besides these limited examples you will need a few libraries.

glMatrix

First of all you will need a linear algebra library with vectors and matrices with dimensions up to 4. If you are a C++ programmer you will probably be a little disappointed finding out that JavaScript does not have operator overload, which makes the code rather ugly.

One of the most commonly used linear algebra libraries for JavaScript is called glMatrix (http://glmatrix.net/). The current version of glMatrix is 2.x. As many other JavaScript libraries it exist in two different versions, a normal version with human readable code and in a minified version, where the source code has been shortened to decrease the file-size and increase the download speed. An example of using the library can be seen below.

The API usually has the output variable as the first parameter. This may seem very odd at first but this allows programmers to use pre-allocated matrices, which avoids temporary matrix objects that eventually has to be cleaned up by the garbage collector.

To save network-bandwidth the code-example above downloads the library from a CDN-server (Content Delivery Network). The idea is similar to shared DLL files used in operating systems; here commonly used libraries are stored on public servers, which means that the browser only needs to download (and cache) the library once even through it might be used on multiple websites.