FZ is a modular, parametrizable lossy compressor framework designed for scientific data, including both floating point numbers and integers. It is applicable in fields such as simulations, AI, and instrumentation. Not only is FZ a production-quality software, but it also serves as a research platform for lossy compression. The framework is both open and transparent. It's "open" in that all interested researchers and students can study or contribute to it, and "transparent" in the sense that all performance improvements are detailed in publications.