A free file format
is a file format
whose full specification is freely available and for which there are no restrictions (e.g. legal or technical) on its use. Users may design and use variations that suit their needs, and contribute enhancements for potential incorporation into the next official version of the format.
Free file formats are good for interoperability and to prevent vendor lock-in. It is a cornerstone in open systems.
Archiving and compression
- 7z — for both archiving and compression.
- SQX — for both archiving and compression.
- PAQ — for compression.
- bzip2 — for compression.
- gzip — for compression.
- tar — for archiving.
- ZIP — for both archiving and compression.
- CSV — spreadsheet file formats.
- CSS — style sheet format.
- DjVu — for scanned images.
- EAS3 — binary file format for floating point data
- ELF — Executable and Linkable Format.
- Hierarchical Data Format — Multi-platform data format for storing multidimensional arrays, among other data structures.
- NZB — for multipart binary files on Usenet.
- NetCDF — for scientific data.
- SDXF — the Structured Data eXchange Format.
- SFV — checksum.
- XML — a general-purpose markup language.
- YAML — human readable data serialization format.