A rather full-featured REPL environment slash IDE for many programming languages.

Calls itself "an open source pastebin with runnable snippets and API". It's a nice and useful REPL environment for many langauges. More simple than repl.it

"Thinking meat! You're asking me to believe in thinking meat!"

A nice 20-minute video on Penrose tiling

"Several designers have played with Corrugated plastics and made some usable boats. Using this type of boatbuilding method results in ultra light boats that are easily folded and transported. Here are a few."