xlnt is a modern C++ library for manipulating spreadsheets in memory and reading/writing them from/to XLSX files as described in ECMA 376 4th edition. The first public release of xlnt version 1.0 was on May 10th, 2017. Current work is focused on increasing compatibility, improving performance, and brainstorming future development goals. For a high-level summary of what you can do with this library, see the feature list. Contributions are welcome in the form of pull requests or discussions on the repository's Issues page. Documentation for the current release of xlnt is available here.