CSS Flexible Box Layout is a module of CSS that defines a CSS box model optimized for user interface design. In the flex layout model, the children of a flex container can be laid out in any direction, and can “flex” their sizes, either growing to fill unused space or shrinking to avoid overflowing the parent. Both horizontal and vertical alignment of the children can be easily manipulated. Nesting of these boxes (horizontal inside vertical, or vertical inside horizontal) can be used to build layouts in two dimensions.
CSS Generated Content is a module of CSS that defines how to add content to an element.
is a module of CSS that defines what types of images can be used (the
type, containing URLs, gradients and other types of images), how to resize them and how they, and other replaced content, interact with the different layout models.
CSS Logical Properties is a module of CSS that defines logical mapping to physical properties to control the layout.
is a CSS module that allows authors to specify XML namespaces
CSS Pages is a module of CSS that defines how page switches are handled, as well as orphans and widows.
CSS Positioning is a module of CSS that defines how to absolutely and relavitely position elements on the page.
CSS Scroll Snap Points is a module of CSS that defines properties and values that provide the author with the ability to control layout through logical, rather than physical, direction and dimension mappings
Selectors define to which elements a set of CSS rules apply.
CSS Shapes is a CSS module that defines geometric shapes for use in CSS values.
CSS Table is a CSS module that defines how to lay out table data.
CSS Text Decoration is a module of CSS that defines features relating to text decoration, such as underlines, text shadows, and emphasis marks.
CSS Transitions is a module of CSS that defines how to create smooth transitions between values of given CSS properties. It allows to create them but also to define their evolution, using timing functions.
CSS User Interface is a CSS module that allows to define the rendering and functionality of user interface related features.
CSS Writing Modes is a CSS module that defines various international writing modes, such as left-to-right (e.g. used by Latin and Indic scripts), right-to-left (e.g. used by Hebrew or Arabic scripts), bidirectional (used when mixing left-to-right and right-to-left scripts) and vertical (e.g. used by some Asian scripts).
CSSOM View is a module that allows to manipulate the visual view of a document, in particular its scrolling behavior.
The Channel Messaging API
allows two separate scripts running in different browsing contexts attached to the same document (e.g., two IFrames, or the main document and an IFrame, two documents via a
, or two workers) to communicate directly, passing messages between one another through two-way channels (or pipes) with a port at each end.