How is the vanilla 1.12 client binary so small?

[bradosia]

The vanilla 1.12 WoW.exe is 4.55 MB and as far as I can tell contains the networking, rendering, and unpacking .mpq file libraries. How in the world did the wow team fit everything into this small executable? The other .dll seem to be for handling audio and windows libraries. I checked the data directory and I found lots of shaders, but nothing else that seems to glue networking, rendering, and UI together. Am I missing another binary with the code for networking, rendering, unpacking .mpq files, UI, and lua interpreting?

[My Channel]

The executable is just a frame. The resources do all the work. The server feeds the quests and such along with scripting and positions and routes of its world occupants.