I've been working on Datasette for a while: it's a tool for publishing static structured data online with a browseable web interface and a JSON API. Until today you had to install various bits and pieces on your computer to use it, but I just released Datasette Publish which provides a web interface that lets you upload data as CSV files and click a button to turn that into an online database and API. My blog has more, including an animated screencast showing how I used it to build an API for exploring California campaign finance data.
Uruk is an open-source Clojure wrapper for MarkLogic's XCC (XML Content Connector) API for Java. [more inside]
A website that lets you browse CC and public domain images. [more inside]