Over the last few pages, we've created some great demos of varying complexity—they show off something of what can be done with animations and how we can use Less.

The trouble is, there's one small but crucial problem here. How many of you have noticed that we've created each demo from scratch, with all the mixins included? I thought so, one of the precepts of Less is DRY or Don't Repeat Yourself.

If we take a look back at Chapter 4, Working with Variables, Mixins, and Functions, one of the subjects we covered was the use of external libraries within our code. Doing this means that we can avoid the need to write lots of mixins—while our examples here might have been a little too simple to warrant the use of an external library, we will definitely need to use at least one external library in a more complex site.

Thankfully, we can continue the same precept of DRY when working with animations; there are a number of Less-based libraries available that handle animation properties...