Google App Engine Mini Profiler

gae_mini_profiler is a quick drop-in WSGI app that provides ubiquitous profiling of your existing GAE projects. It exposes both RPC statistics and standard profiling output for users of your choosing on your production site. Only requests coming from users of your choosing will be profiled, and others will not suffer any performance degradation.

SocketStream

SocketStream is a new full stack web framework built around the Single-page Application paradigm. It embraces websockets, in-memory datastores (Redis), and client-side rendering to provide an ultra-responsive experience.

Perceptual Image Difference Utility

PerceptualDiff is an image comparison utility that makes use of a computational model of the human visual system to compare two images.

Sitebricks

Sitebricks is a simple set of libraries for web applications. Sitebricks focuses on early error detection, low-footprint code, and fast development. Powered by Guice, it also balances idiomatic Java with an emphasis on concise code.

Apache Lucy

Apache Lucy is full-text search engine library written in C and targeted at dynamic languages. It is a 'loose C' port of Apache Lucene.