Abstract
We present possible programs to analyze lens systems with the GTC. Firstly, redshift and stellar velocity dispersion of galaxies involved in gravitational lensing phenomena can be provided from spectroscopy. Secondly, we could use narrow-band images of lens systems covering a wide spectral range to obtain extinction curves of lens galaxies, macrolens flux ratios, and soon. Finally, we intend to study systems with particular difficulties (very faint and/or extremely compact). In these cases, a Gravitational Lenses service program would be suitable to measure time delays, discuss on microlensing variability, and the like.
