Samtools is a mature, production-grade command-line toolkit for processing high-throughput sequencing alignment data in SAM, BAM, and CRAM formats. It provides dozens of subcommands covering the full NGS workflow: format conversion (view), sorting, indexing, duplicate marking (markdup), mate-pair fixing (fixmate), depth/coverage calculation, variant calling preparation (mpileup), consensus calling, amplicon analysis, and comprehensive statistics (stats/flagstat). The architecture is a single C binary built on the htslib library, with each subcommand implemented as a separate source file dispatched from bamtk.c. The codebase is well-structured with reusable abstractions for pileup iteration, BED interval indexing, temporary file management, and global option handling. It is actively maintained with extensive regression tests, cross-platform CI (Linux, macOS, Windows, FreeBSD, OpenBSD, Solaris), and a large user community in bioinformatics.