Fathom can be implemented in a browser, extensions and even server-side software. It is a data-flow language like Prolog.
Mozilla’s developers have designed Fathom to calculate DOM nodes based on user-specified conditions, annotations and a system of types. This process helps the framework to extract meaning from parts like address forms, previous/next buttons and textual content found on the website.
Smart enough even at early stage
According to Mozilla’s Senior Staff Software Architect Erik Rose, the framework is still in the early stage of development. It, nevertheless, enables the browser to identify meaningful parts on a page and show the summary.