Libravatar is software that allows domain owners to control how avatars (profile pictures) are served to other Web sites. It implements a modified version of the Gravatar API, adding a few features such as federation, LDAP authentication, and OpenID support. Libravatar powers libravatar.org.
Wise is an experimental Web-based notebook and simple computer algebra system based on the Pure programming language. The goal is to provide a digital scratchpad that makes manipulating symbolic expressions fast, accessible, and extensible. Wise is a bottom-up approach to symbolic math written entirely in C and Python. It does not depend on any external math software or libraries (such as Maxima, Axiom, Mathematica, etc.).