The Mer Wiki now uses your Mer user account and password (create account on https://bugs.merproject.org/)
Mer is targetted at devices and delivers software as packages, usually collected into device images.
Mer images are made using a low-level tool called mic. For larger deployments where images need to be shared or created for automation purposes this tool is wrapped into an image creation service called IMG.
Image creation is controlled by a .ks or kickstart file. This file contains information mic needs to select and configure packages.