The architectural structure of a donutag comprises of a few, to an infinite number of small modules assembled on-the-fly. The product design calls for additional modules to be added to the base group — sort of slappped onto the outside without inherent priority. This allows the additional modules to be swapped out and updated regularly, without affecting the core group. This allows for unlimited expandability. Additional modules — or engines — can be anything the user might find useful — for instance; a calculator to tag-team with an inventory control engine for a retail store manager; a news or weather engine; a cash register for a small business; or flight and flight booking information for a tourist. Imagination is the only limit.