A presentation of the design of the telescope and instrumentation for the 39-m E-ELT. The talk will focus on challenges and prototyping undertaken during the detailed design phase of the 1.1-Billion Euro E-ELT. From large optics and serial production of precision optical components to fast real time wavefront control the E-ELT is challenging both institutes and industrial partners. The E-ELT is planned to start construction in 2012.