The columns are organized left-to-right by the date an API in that column was first implemented. The rows are organized by the date they were first proposed.

The first row represents technologies that still work, but are superseded or obsoleted by newer technologies. The second-to-last row is deprecated or abandoned APIs. These may have been implemented before and removed, or only partly implemented. The last row is proprietary or vendor-specific APIs. These only ever worked in one browser.

The darkness and lightness represents the browser support of an API. The redness represents how active an API's proposal or specification is.

• Date links to the Specification
• Element abbreviation links to What can this do? (Demo, Playground, or Reference)
• Details links to How can I learn this? Guide
• Background links to browser support (For most APIs, caniuse.com. For in-progress APIs, implementation progress pages.)

Simply edit the HTML file. :) It uses nicely formatted semantic HTML. The CSS is inside the file.