Segyio is a small LGPL licensed C library for easy interaction with SEG-Y formatted seismic data, with language bindings for Python and Matlab. Segyio is an attempt to create an easy-to-use, embeddable, community-oriented library for seismic applications. Features are added as they are needed; suggestions and contributions of all kinds are very welcome. To catch up on the latest development and features, see the changelog. To write future proof code, consult the planned breaking changes.