A directory of free APIs for use in software and web development.
An open source semantic network (Creative Commons license) for AI and ML development. Semantic nets encode the meaning of words and concepts for information processing systems. Seems to encompass several spoken languages. Curated to avoid stereotypes. Still an active project. Data elements have a concept of external URLs, which link to other data sources with machine-parseable data related to that element.
Not true but hilarious facts about security and cryptography guru Bruce Schneier.