Open Source, released under the MIT License.
The simple and effective RockSolid Columns Plugin allows you to divide your articles and modules into multiple columns. And the responsive behavior of the content can be directly defined for every single element.
Similar to the Contao core accordion element you can either wrap single or multiple elements. And controlling the proportions of uneven columns is as simple as creating even groups.
If you want you can safely use your own CSS to control the look and function of the columns. Everything without using YAML or inline styles.
You are in total control of the proportions and column widths. This way you can define uneven gridsets easily and aren't bount to even distribution.
You can split virtually any type of content into multiple columns. And by using the column wrapper element you can add any number of elements to a column.