Mixins are divided into categories in a way how it done in the compass' reference. See sources to find what is already implemented.
To start using this set, simply extract an archive into folder where your
less files lie, rename extracted directory to
compless and put
@import "compless/all" on the top of your stylesheet.
The main purpose of this project is to give a developer mixins set similar to compass' one. So, if you want to create a pull request, make sure that new functionality as similar to compass' analogues as possible.
However, sometimes compass doesn't fit our need. Because of this we have support for mixins called "extensions". They all have "e-" prefix.