  We demonstrate experimentally the full tunability of a coherent femtosecond
source in the whole ultraviolet spectral region. The experiment relies on the
technique of high-order harmonic generation driven by a near-infrared
parametric laser source in krypton gas. By tuning the drive wavelength in the
range between 1100 to 1900 nm, we generated intense harmonics from near to
extreme ultraviolet. A number of photons per shot of the order of 10^7 has been
measured for the first harmonic orders. Many novel scientific prospects are
expected to benefit from the use of such a table-top tunable source.
