A saltire, also called Saint Andrew’s Cross or the crux decussata, is a heraldic symbol in the form of a diagonal cross. The word comes from the Middle French sautoir, Medieval Latin saltatoria (“stirrup”).
On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one’s intellectual curiosity.