Checksumit

Checksumit is a cross-platform open-source command-line utility designed to compute and verify checksums for files and software packages. It aims to simplify data integrity workflows in software distribution, backups, and archival processes by providing a consistent interface across operating systems.

Features include support for multiple algorithms (MD5, SHA-1, SHA-256, SHA-512, SHA-3, and BLAKE2), both hex and base64 outputs, generation of manifest files, and a verify mode that checks files against a given checksum manifest. It offers streaming I/O to handle large files, quiet and verbose modes, and integration hooks for CI pipelines and packaging tools. The design emphasizes a small footprint, clean error reporting, and pluggable backends for different hash libraries.

Usage is straightforward: checksumit sum file1.bin file2.iso computes checksums for the listed files; checksumit verify manifest.sha256 checks that the files match the checksums in the manifest. The tool is implemented in a portable language and is distributed via standard package managers, with builds for Windows, macOS, and Linux.

In terms of development, checksumit is maintained by an active community and released under an OSI-approved open-source license. It is designed to interoperate with common distribution formats and manifests, and to complement existing verification tools. See also hash functions, checksum, and software distribution integrity.