GLIMPSE is a SIRTF Legacy Science Program designed to map the inner two-thirds of the Galactic disk using the IRAC instrument at 3.6, 4.5, 5.8, and 8.0 μm. The survey covers Galactic latitudes |b| ≤ 1° and longitudes |l| = 10° to 65°, focusing on the outer ends of the Galactic bar, the molecular ring, and the inner spiral arms. The survey will produce a high-reliability point source catalog, a point source archive, and mosaicked images. The data will be used to study the structure of the inner Galaxy, the distribution of stars, and the statistics and physics of star formation. The survey will also provide insights into the nature of the central bar and the relationship between the molecular ring and star formation. The data will be made available to the community for a wide range of astrophysical investigations, including studies of stellar populations, photo-dissociation regions, extinction, and serendipitous discoveries. The survey will also complement other datasets, such as 2MASS, MSX, and radio surveys, to provide a comprehensive understanding of the Galaxy's structure and star formation processes. The GLIMPSE data will be used to study the distribution and statistics of star formation throughout the Galaxy, and to determine whether the Galaxy is a ringed spiral. The survey will provide a panoramic view of the inner Galaxy, with high angular resolution and minimal extinction, and will be a valuable resource for future studies of the Milky Way.GLIMPSE is a SIRTF Legacy Science Program designed to map the inner two-thirds of the Galactic disk using the IRAC instrument at 3.6, 4.5, 5.8, and 8.0 μm. The survey covers Galactic latitudes |b| ≤ 1° and longitudes |l| = 10° to 65°, focusing on the outer ends of the Galactic bar, the molecular ring, and the inner spiral arms. The survey will produce a high-reliability point source catalog, a point source archive, and mosaicked images. The data will be used to study the structure of the inner Galaxy, the distribution of stars, and the statistics and physics of star formation. The survey will also provide insights into the nature of the central bar and the relationship between the molecular ring and star formation. The data will be made available to the community for a wide range of astrophysical investigations, including studies of stellar populations, photo-dissociation regions, extinction, and serendipitous discoveries. The survey will also complement other datasets, such as 2MASS, MSX, and radio surveys, to provide a comprehensive understanding of the Galaxy's structure and star formation processes. The GLIMPSE data will be used to study the distribution and statistics of star formation throughout the Galaxy, and to determine whether the Galaxy is a ringed spiral. The survey will provide a panoramic view of the inner Galaxy, with high angular resolution and minimal extinction, and will be a valuable resource for future studies of the Milky Way.