GMAP is a standalone program designed for mapping and aligning cDNA sequences to a genome, offering improved speed and accuracy compared to existing programs. It uses a minimal sampling strategy for genomic mapping, oligomer chaining for approximate alignment, sandwich dynamic programming (DP) for splice site detection, and statistical significance testing for microexon identification. GMAP can handle large sequence sets efficiently, with minimal startup time and memory requirements. It performs well in various scenarios, including high-quality and error-prone sequences, and has been shown to outperform other programs in terms of accuracy and speed. The program is available for download and can be run on computers with as little as 128 MB of RAM.GMAP is a standalone program designed for mapping and aligning cDNA sequences to a genome, offering improved speed and accuracy compared to existing programs. It uses a minimal sampling strategy for genomic mapping, oligomer chaining for approximate alignment, sandwich dynamic programming (DP) for splice site detection, and statistical significance testing for microexon identification. GMAP can handle large sequence sets efficiently, with minimal startup time and memory requirements. It performs well in various scenarios, including high-quality and error-prone sequences, and has been shown to outperform other programs in terms of accuracy and speed. The program is available for download and can be run on computers with as little as 128 MB of RAM.