PredictionIO is an open source content prediction tool used for content suggestions.

PredictionIO is laced with delicious features:

• Machine-learning algorithms for tweaking the content suggestions;
• Fast and painless implementation;
• Scalable — can handle large amounts of data.

It’s built on top of frameworks such as Hadoop and Cascading, and has SDKs for Java, Python and Ruby.

Ozone Widget Framework (OWF) is a government-developed lightweight widget framework.

The idea behind this framework is that it’s actually a web application that you deploy on your server where it’s used for developing widgets.

OWF works on most modern browsers, including IE7. The widgets themselves are decentralized and ran inside of iFrames, allowing for cross-domain interaction.

jsoup is a Java library for parsing HTML5 data.

It provides a convenient API for extracting and manipulating HTML5 data.

jsoup has a number of uses: parsing user comments; extract HTML data; beautify HTML output; etc.

It’s pertinent to note that jsoup can also parse invalid code, or, as the devs put it: “jsoup is designed to deal with all varieties of HTML found in the wild”.

GreenDroid is a library for making Android UI development easier.

GreenDroid’s main advantages over other similar Android libraries is its concise, powerful set of UI-management features.

The library supports Android 1.6. It might support Android 1.5, but it’s less likely to do so.

GreenDroid is an awe-inspiring solution for making consistent UI’s for Android devices.

Friar is a framework for publishing interactive eBooks on Android devices. The eBooks must be written in HTML5.

The framework is heavily inspired by Baker, but the code is mainly original.

Friar eases the publishing process fundamentally, by providing a single coding ground, a flexible format and easy publishing.

If you’ve been thinking about publishing your books to the Android app store, friar could be the perfect solution for you.

Spark is a Java micro framework for creating web applications with minimal effort.

Spark is similar to Sinatra in terms of structure, but is instead meant for developers who want to develop in pure Java. (Sinatra runs on Ruby.)

Spark, unlike many similar frameworks, doesn’t require XML configuration, and altogether tries to provide a framework for rapid app development in a clean environment.

The framework has a basic routing system and offers a number of useful methods (that are rather common in other frameworks, too) for building RESTful web applications.