Several addon formats are supported by Doomsday (and Snowberry) and are intended for a variety of different purposes. Some are inherited from existing games (such as WAD from DOOM 9;93) where others are entirely new, designed to make the modding process easier for end users.

The following diagram explains the high-level organization of these formats and their relationship with one another:

• addon_bundle
• plugin_bundle (Snowberry extension)
• ZIP/PK3
• wad (lmp)

• ded
• deh
• info (metadata)
• manifest

• Box (a folder)

• Packages (1.15 →)