The Immuno Polymorphism Database (IPD) and the IMGT/HLA database are central resources for the study of immune system polymorphism. The IPD provides a centralized platform for curating and publishing locus-specific databases related to the Major Histocompatibility Complex (MHC) and other immune-related genes. The IMGT/HLA database is the primary database within IPD, containing sequences of the human MHC. It was first released in 1998 and has since been updated regularly to include publicly available sequences. The database is used by the transplantation community, as HLA matching is critical for successful organ and bone marrow transplants. The IMGT/HLA database ensures high-quality sequence data by requiring rigorous validation and curation, including the use of bioinformatics tools and expert review. The database also supports the analysis of next-generation sequencing (NGS) data, which has increased the volume and complexity of sequence data. This has led to the need for more comprehensive and accurate databases to manage the high polymorphism of HLA genes. The IMGT/HLA database has been updated to accommodate new sequencing technologies and to ensure that the nomenclature remains accurate and relevant. The database also provides tools for sequence analysis, including alignment and variant reporting. The IPD also includes other databases such as IPD-KIR, IPD-MHC, IPD-HPA, and IPD-ESTDAB, which cover various immune-related genes and antigens. These databases are curated by specialist groups and nomenclature committees to ensure accuracy and consistency. The IPD project continues to develop new tools and methods to address scientific advancements and user feedback. The IMGT/HLA database is a model for other highly polymorphic gene systems, such as the KIR genes, and has been used as a reference for the nomenclature of other MHC-related genes in different species. The database is available online and is freely accessible, with a Creative Commons license allowing for commercial use and distribution. The IPD project is supported by various funding sources and is a key resource for immunogenetics research and clinical applications.The Immuno Polymorphism Database (IPD) and the IMGT/HLA database are central resources for the study of immune system polymorphism. The IPD provides a centralized platform for curating and publishing locus-specific databases related to the Major Histocompatibility Complex (MHC) and other immune-related genes. The IMGT/HLA database is the primary database within IPD, containing sequences of the human MHC. It was first released in 1998 and has since been updated regularly to include publicly available sequences. The database is used by the transplantation community, as HLA matching is critical for successful organ and bone marrow transplants. The IMGT/HLA database ensures high-quality sequence data by requiring rigorous validation and curation, including the use of bioinformatics tools and expert review. The database also supports the analysis of next-generation sequencing (NGS) data, which has increased the volume and complexity of sequence data. This has led to the need for more comprehensive and accurate databases to manage the high polymorphism of HLA genes. The IMGT/HLA database has been updated to accommodate new sequencing technologies and to ensure that the nomenclature remains accurate and relevant. The database also provides tools for sequence analysis, including alignment and variant reporting. The IPD also includes other databases such as IPD-KIR, IPD-MHC, IPD-HPA, and IPD-ESTDAB, which cover various immune-related genes and antigens. These databases are curated by specialist groups and nomenclature committees to ensure accuracy and consistency. The IPD project continues to develop new tools and methods to address scientific advancements and user feedback. The IMGT/HLA database is a model for other highly polymorphic gene systems, such as the KIR genes, and has been used as a reference for the nomenclature of other MHC-related genes in different species. The database is available online and is freely accessible, with a Creative Commons license allowing for commercial use and distribution. The IPD project is supported by various funding sources and is a key resource for immunogenetics research and clinical applications.