Four short links: 19 April 2012

Superfastmatch — open source text comparison tool, used to locate plagiarism/churnalism in online news sites. You can pull out the text engine and use it for your own “find where this text is used elsewhere” applications (e.g., what’s being forwarded out in email, how much of this RFP is copy and paste, what’s NOT boilerplate in this contract, etc.). (via Pete Warden)
Ten Design Principles for Engaging Math Tasks (Dan Meyer) — education gold, engagement gold, and some serious ideas you can use in your own apps.
Clustering Related Stories (Jenny Finkel) — description of how to cluster related stories, talks about some of the tricks. Interesting without being too scary.
Prince of Persia (GitHub) — I have waited to see if the novelty wore off, but I still find this cool: 1980s source code on GitHub.

Text Similarity, Designing Engagement, Clustering Stories, and Prince of Persia