ESP in Rust refers to a type of hack that allows players to see other players through walls or at any distance by having their name IDs on the screen at all times. It is called ESP after "extra sensory perception" but is essentially a wall hack that allows players to see other players or even items through walls. Some ESP hacks also include auto-aim.

It is important to note that ESP is a hack and is not a legitimate feature of the game. Players who use ESP hacks are cheating and can ruin the game for others. Rust is built carefully to prevent ESP hacks from accessing certain information, but they can still see anything their client sees.

In a different context, Rust std library development using ESP devices is built on the ESP-IDF (Espressif IoT Development Framework), which is an open-source framework for building IoT applications. Rust layers are introduced on top of the existing framework using the foreign function interface (FFI) .

In summary, ESP in Rust refers to a type of hack that allows players to see other players through walls or at any distance, and it is not a legitimate feature of the game. In a different context, Rust std library development using ESP devices is built on the ESP-IDF using the FFI.