From the IBM release: IAccessible2 is a new accessibility API which complements Microsoft's earlier work on MSAA. This API fills critical accessibility API gaps in the MSAA offering. IAccessible2 was created out of necessity to produce a usable and accessible OpenDocument Format (ODF) based office suite for the Commonwealth of Massachusetts. IAccessible2 is an engineered accessibility interface allowing application developers to leverage their investment in MSAA while also providing an Assistive Technology (AT) access to rich document applications such as the IBM Workplace productivity editors and web browsers such as Firefox. The additional function includes support for rich text, tables, spreadsheets, Web 2.0 applications, and other large mainstream applications.