What languages ​​can be written under Arduino UNO R3 (except C#)?

Question

Arduino

There are several questions about Arduino.
1. In what languages ​​can I write under Arduino UNO R3 (except C#)?
2. Can this be done in the Eclipse development environment? If yes, what is needed for this?
3. Does anyone know if the motors in this gearbox work asynchronously? (independent of each other)?
4. Can the relay from this robot be attached to the Arduino ( here is the documentation)? Is this scheme suitable for this?

Answer 1

1. Arduino is programmed in C++
2.
yes 3. yes
4. yes