I have been working on a website aimed at teaching programming and computer science through quick examples in the form of exercises. It is called "
Computer Science by Example":
https://cscx.org/The exercises start very simple (
e.g. read two numbers and print their sum) then increase in difficulty and complexity gradually (
e.g. solving the change-making problem). The website has an "online judge" functionality where students can submit their solutions which are tested and graded automatically without human intervention. It currently supports solutions in
Lua and additionally: Python, C, C++, C#, Haskell, Java, _javascript_ and Ruby.
The exercises are useful not only to first time programmers, but also to experienced programmers migrating to using Lua.