What are these Mod Pack things?
Mod Packs are custom collections of Mods that users can create to make it easy to share the mods they use with others. Mod Packs can also be used as a way of saving a set of mods to use in the main Craft Search.
You can create a Mod Pack by hand picking the mods you want and you can also (if you use CKAN) upload a file from CKAN to automatically select the mods you have installed. Every Mod Pack has a CKAN file which you can download and give to the CKAN mod manager which will then automatically install the mods from the mod pack. If you don't use CKAN you can click on the mods listed and find where you can download it from. If you create a mod pack on the main search page it will be created with any mods you have selected in the search filters. Or if you create one while on a modded craft's page it will have the mods which that craft uses. You can always add/remove mods later. Mod Packs with a green highlight are the 'current mod pack' for that user.