Inspired by an example question before beta, can I make the Leonardo bootloader take less that 8 seconds to run? It is very slow and I want to speed it up somehow.
Detailed instructions on how to shorten the bootloader time of Leonardo etc. are explained [here] (as stated by @Chris Stratton).
The crux of the matter was to redefine the timeout period
/* ./arduino/hardware/arduino/bootloaders/caterina/Caterina.c */ #define TIMEOUT_PERIOD 8000
to a lower value.
However I do not have such issues with Leonardo it boots very fast. So this issue depends on your environment.
There is also OptiBoot, an alternative bootloader that really boots faster link: