A. The Land Information System (LIS) is an open source flexible land-surface modeling and data assimilation software framework developed here at NASA Goddard within the Hydrological Sciences Laboratory. GLDAS, NLDAS, NCA-LDAS, and FLDAS are specific uses of the LIS software, and these LDAS projects have produced land-surface forcing data and model output going back many decades and continuing to near real-time. Links to download LDAS datasets are located on the right side of this FAQ. There is no "LIS data" - unless, of course, you use LIS yourself to generate your own!