LOBSTER is a software tool for chemical bonding analysis based on plane-wave based density functional theory (DFT) output. It enables the extraction of chemical bonding information from first-principles simulations in solid-state and materials chemistry. LOBSTER incorporates analytic projection routines and offers improved functionality, allowing for the calculation of atom-projected densities of states (pDOS), projected crystal orbital Hamilton population (pCOHP) curves, and the recently introduced bond-weighted distribution function (BWDF). The software is freely available for non-commercial research. The paper describes recent developments in LOBSTER, including improved projection quality measures such as "absolute spilling" and "root-mean-square of the projection (RMSp)", and the use of Löwdin's symmetric orthonormalization to improve correspondence with traditional COHP analysis. LOBSTER also supports user-defined rotations of the basis functions, enhancing its flexibility. The software processes delocalized PAW wavefunctions calculated with VASP or ABINIT and performs projection into an auxiliary LCAO basis, making bond-analytic tools such as pDOS, pCOOP, and pCOHP accessible for state-of-the-art plane-wave based PAW simulations. LOBSTER has been applied to a wide range of systems, including phase-change materials, surface chemistry, and magnetic materials. It has been used to analyze the bonding in materials such as GeTe, α-iron, and Ru monolayers, providing insights into the electronic structure and bonding characteristics. The paper also discusses the technical aspects of LOBSTER, including its implementation in modern, object-oriented C++ and its use of the Boost library for various algorithms and concepts. LOBSTER is a multiplatform tool that supports Linux, Windows, and OS X, and it uses efficient matrix and vector algebra for data structures and algorithms. It is parallelized using OpenMP and uses memory mapped I/O to read large chunks of input data from the file system. In conclusion, LOBSTER is a powerful tool for chemical bonding analysis based on DFT calculations, providing a range of bond-analytic tools and improved projection quality measures. It has been successfully applied to a wide range of systems and has contributed to the understanding of chemical bonding in various materials.LOBSTER is a software tool for chemical bonding analysis based on plane-wave based density functional theory (DFT) output. It enables the extraction of chemical bonding information from first-principles simulations in solid-state and materials chemistry. LOBSTER incorporates analytic projection routines and offers improved functionality, allowing for the calculation of atom-projected densities of states (pDOS), projected crystal orbital Hamilton population (pCOHP) curves, and the recently introduced bond-weighted distribution function (BWDF). The software is freely available for non-commercial research. The paper describes recent developments in LOBSTER, including improved projection quality measures such as "absolute spilling" and "root-mean-square of the projection (RMSp)", and the use of Löwdin's symmetric orthonormalization to improve correspondence with traditional COHP analysis. LOBSTER also supports user-defined rotations of the basis functions, enhancing its flexibility. The software processes delocalized PAW wavefunctions calculated with VASP or ABINIT and performs projection into an auxiliary LCAO basis, making bond-analytic tools such as pDOS, pCOOP, and pCOHP accessible for state-of-the-art plane-wave based PAW simulations. LOBSTER has been applied to a wide range of systems, including phase-change materials, surface chemistry, and magnetic materials. It has been used to analyze the bonding in materials such as GeTe, α-iron, and Ru monolayers, providing insights into the electronic structure and bonding characteristics. The paper also discusses the technical aspects of LOBSTER, including its implementation in modern, object-oriented C++ and its use of the Boost library for various algorithms and concepts. LOBSTER is a multiplatform tool that supports Linux, Windows, and OS X, and it uses efficient matrix and vector algebra for data structures and algorithms. It is parallelized using OpenMP and uses memory mapped I/O to read large chunks of input data from the file system. In conclusion, LOBSTER is a powerful tool for chemical bonding analysis based on DFT calculations, providing a range of bond-analytic tools and improved projection quality measures. It has been successfully applied to a wide range of systems and has contributed to the understanding of chemical bonding in various materials.