Or using not and and.

Used De Morgan's law to figure this one out. Not(a or b) = Not(a) and Not(b).
Shorter Or using just Nand.

Left the not & and version in.
Remove the not and and version
Simple implementation of Xor.

Or(And(Not(a), b), And(a, Not(b)))
Simplify Xor to use 5 Nands.
Multiplexor with not and and or
Nand version of Mux

It is so cool how the nots collapse when you translate the higher level gates to nand.
DeMultiplexor
Nand version of the DMux.

Not sure if this is the simplest version.
Not16 with nands
Fix indentation
And16 with nands
Remove extra whitespace
Simple implementation of 16 bit or
Or16 with just nands.
Mux16 with nands.

Why? I don't know. Because I could?