Starbursts at z >~6: from the present to Herschel and ALMA

The SED of the lensed z=6.56 galaxy HCM6A behind the cluster Abell 370 has been analysed. We find clear indications for the presence of dust in this galaxy, and we estimate the properties of its stellar populations (SFR, age, etc.). From its estimated luminosity, L~(1-4)e.+11 Lsun, this galaxy ranks as a luminous infrared galaxy. This case is then used to examine the detectability of high-z galaxies with Herschel and ALMA. It is evident that with the use of strong gravitational lensing SPIRE/Herschel observations could provide very interesting information on z > 5 galaxies. Strong synergies between ground-based near-IR instruments on 8-10m class telescopes and ELTs, Herschel, the JWST, and ALMA can be expected for the exploration of the first galaxies in the Universe.