Small programs that read a file without the application that made it. They run on your machine, upload nothing, and never rewrite the file.
The set is deliberately narrow: signature check, checksums, archive peek, EPS repair, layer listing, raw decoding, CAD inspection, font inspection, metadata strip, merging, batch rename, disk-image mounting, universal viewing, converting.
How the tools are described
One page per program. A page says what the program reads, what it reports, and what it refuses to touch. Anything the program does not do is stated on the page rather than left for the reader to discover, which is the main reason these pages exist separately from the download.
The tools are rebuilt with each release and use the same catalogue as the format pages, so a header described on a format page is the header the tool checks. When a tool and a format page disagree, the format page is treated as the one that is wrong.