FEBio is a finite element (FE) software suite designed specifically for computational solid biomechanics. Developed by researchers from the University of Utah and Columbia University, FEBio addresses the limitations of commercial software in this field by offering a tailored, open-source solution. The software supports both quasi-static and dynamic analyses, featuring a wide range of constitutive models and boundary conditions relevant to various biomechanical applications. FEBio is written in C++, optimized for performance on modern computer architectures, and includes pre- and post-processing tools (PreView and PostView) for model definition and visualization. The paper provides an overview of FEBio's theoretical framework, key features, and verification results, demonstrating its accuracy and reliability through comparisons with analytical solutions and results from other established FE codes. FEBio is intended to serve as a flexible and extensible tool for researchers and developers in computational biomechanics, with ongoing development and support to enhance its capabilities.FEBio is a finite element (FE) software suite designed specifically for computational solid biomechanics. Developed by researchers from the University of Utah and Columbia University, FEBio addresses the limitations of commercial software in this field by offering a tailored, open-source solution. The software supports both quasi-static and dynamic analyses, featuring a wide range of constitutive models and boundary conditions relevant to various biomechanical applications. FEBio is written in C++, optimized for performance on modern computer architectures, and includes pre- and post-processing tools (PreView and PostView) for model definition and visualization. The paper provides an overview of FEBio's theoretical framework, key features, and verification results, demonstrating its accuracy and reliability through comparisons with analytical solutions and results from other established FE codes. FEBio is intended to serve as a flexible and extensible tool for researchers and developers in computational biomechanics, with ongoing development and support to enhance its capabilities.