The Spider is a complete object-oriented environment for machine learning in Matlab. Aside from ease of use for base learning algorithms, algorithms can be plugged together and can be compared with, for example, model selection, statistical tests, and visual plots. This gives all the power of objects (reusability, the ability to plug together, sharing of code), but also all the power of Matlab for machine learning research.
The XEVM is an XML processing engine. It's a multi-threaded, Pub/Sub environment for dynamic programming on an event-driven state machine with TCP communications, tight fault free memory management, powerful set algebra, and a magical database. It is 100% C++ (25,000 LOC), with a thin porting layer; there are implementations for POSIX (Mac/Linux) and Win32. The XEVM is for processing XEPL (the Xepl Engine Programming Language).
pyECTOR is a chatterbot which learns from what people say. It is based on an artificial intelligence architecture that is inspired by Copycat, an AI system from Mitchell and Hofstadter. The Concept Network it uses is a mix between neural and semantic networks. It uses co-occurrences to compute the influence of one semantic node on another. The links are statistically weighted.
RuStem is a fast Ruby module with the the Porter stemming algorithm (a process for removing the commoner morphological and inflexional endings from words in English; its main use is as part of a term normalisation process that is usually done when setting up Information Retrieval systems).