I was lucky enough to be in the Lua Workshop 2013. Held in Toulouse.
I had lots of fun there, both in the conference and outside it. For me, one of the most important topics raised were the speciation of the Lua world. Stock Lua, LuaJIT, openresty, luvit ... Many different environments for which lots of packages do not work in different environments (lua-redis and lua-resty-redis, for example).
This 'problem' extends to other parts of the language and comunity, like packaging. You cannot use luarocks for Luvit, or, the openresty packages are not in LuaRocks. The community is aware of that, and trying to find some compromises to create a healthy ecosystem. I loved when LuaDist, LuaRocks and the debian packager of lua started an 'impro' discussion on issues they had, pros and cons.
Other talks were also amazing, like Roberto's one: 'Lua, past present and future'. Great way to expose the Lua history and philosophy and reasoning behind some of the features that Lua came to have nowadays. (Spoiler for the future: They are working on Macros!!!)
People modifying the vm to adapt it to their needs were also really wicked cool things we saw there.
Thanks to 3scale for sponsoring my trip, and to the Lua community for being so awesome :).