ATK

ATK (Accessibility Toolkit) is the accessibility framework for the Linux desktop environment, providing an API through which applications expose their user interface elements to assistive technologies such as the Orca screen reader. ATK defines interfaces for accessible objects — including their roles, states, names, relationships, and actions — that applications implement so assistive technologies can discover and interact with UI components. ATK works in conjunction with AT-SPI (Assistive Technology Service Provider Interface), an inter-process communication protocol that allows assistive technologies running in separate processes to access application accessibility information. In the web context, the Mozilla/Firefox browser implements ATK to expose web content to Linux screen readers, making it one of the three major platform accessibility APIs alongside Microsoft's MSAA/UIA and Apple's NSAccessibility.