I've been working on a console-mail client which is configured and scripted entirely in Lua:
While I cannot pretend it is significant, it is new/fresh/recent. I'm just going through a transition to the GMime mime library, but beyond that the code is stable and I've used the client for the past few month or so, replacing mutt as my main client.
Now that I'm using it I'm finding interesting things to do all the time, using Lua has allowed me to move from having a mostly-extensible client (mutt) to having a __very__ extensible client.