CTF2 was originally designed to demonstrate the feasibility of two-beam acceleration with high current drive beams and a string of 30 GHz CLIC accelerating structure prototypes (CAS). This goal was achieved in 1999 and the facility has since been modified to focus on high gradient testing of CAS's and 30 GHz single cell cavities (SCC). With these modifications, it is now possible to provide 30 GHz RF pulses of more than 150 MW and an adjustable pulselength from 3 to 15 ns. While the SCC results are promising, the testing of CAS's revealed problems of RF breakdown and related surface damage. As a consequence, a new R&D program has been launched to advance the understanding of RF breakdown processes, to improve surface properties, investigate new materials and to optimise the structure geometries of the CAS's. In parallel the construction of a new facility named CTF3 has started. CTF3 will mainly serve two purposes. The first is the demonstration of the CLIC drive beam generation scheme. CTF3 will acceler-ate a 1.54 ms long electron pulse of 3.5 A in a fully beam-loaded S-band linac. The linac beam pulse is compressed in isochronous rings to 140 ns pulse-length, 35 A beam current and a micro-bunch repetition rate of 15 GHz. The second purpose of CTF3 is to test CAS's with nomi-nal CLIC parameters. For this reason the drive beam extracted from the combiner ring is transported through a string of 30 GHz power extraction cavities feeding CAS's. The 30 GHz acceleration is measured with a probe beam provided by a small, separate S-band linac
