JSPraat aims to provide a JS compatibility layer to Praat file formats. It currently provides a browser-side view for Praat's TextGrid format. TextGrid is a popular format for annotated speech, supporting multiple tiers of two different types of annotations. This project began as a component of the Reciprosody file browser and is portable enough to be used anywhere else.
Like Praat, JSPraat displays a waveform synchronized to a TextGrid below. As you move/zoom around the TextGrid or the waveform your view is kept synchronized. The waveform is drawn via HTML Canvas. The TextGrid is drawn with the help of the enormously useful D3.js library.
Currently JSPraat only supports a view of the TextGrid. The long-term goal of the project is to also have editing features: adding and removing elements from tiers, adding tiers, and etc. Such features would allow for greater utility from web-based data collection platforms like Amazon Mechanical Turk - eliminating the need for a secondary alignment phase.