The browsercompat project is a part of a long process to improve the quality of compatibility data on the web.
The Mozilla Developer Network (MDN) hosts a huge amount of documentation of web technologies, including browser compatibility tables, such as data about the CSS display property. This data is maintained by the MDN community to keep it accurate and up-to-date. These hand-written tables are useful for developers, but are challenging to maintain, hard to sync across translations, and are unsuitable as a data source for scripts or alternate displays.
In December 2013, Mozilla began planning for a significat update to the technology used to maintain the compatibility tables. In June 2014, work started on the browsercompat project, to define the data schema, build a data store, and provide an API for reading and contributing compatibility data. In February 2015, the service began extracting data from MDN pages. Later this year, MDN will start displaying compatibility data from the API, and new data contributions will be made to the service rather than as MDN page edits.
Some useful links: