  General results from a 3-5 micron spectroscopic survey of nearby low-mass
young stellar objects are presented. L and M-band spectra have been obtained of
\~50 low mass embedded young stars using the ISAAC spectrometer mounted on
UT1-Antu at Paranal Observatory. For the first time, a consistent census of the
CO, H2O ices and the minor ice species CH3OH and OCN- and warm CO gas present
around young stars is obtained, using large number statistics and resolving
powers of up to R=10000. The molecular structure of circumstellar CO ices, the
depletion of gaseous CO onto grains in protoplanetary disks, the presence of
hot gas in the inner parts of circumstellar disks and in outflows and infalls
are studied. Furthermore, the importance of scattering effects for the
interpretation of the spectra have been addressed.
