by @devinsays
json
Mockaroo
Mockaroo lets you generate thousands of rows of realistic test data in CSV, JSON, SQL, and Excel formats.
Timeline JS
Beautifully crafted timelines that are easy, and intuitive to use. TimelineJS can pull in media from different sources. It has built in support for: Twitter, Flickr, Google Maps, YouTube, Vimeo, Dailymotion, Wikipedia, SoundCloud and more media types in the future.
Creating one is as easy as filling in a Google spreadsheet or as detailed as JSON.
JSON Editor
An online JSON and XML data editor that also has an offline AIR-powered product.