What GUI toolkits are available?
This wiki page is a good start. Probably the most full-featured and well-maintained binding is wxLua An easy and lightweight alternative for more casual scripting is IUP; both IUP and wxLua are part ofLua for Windows but they are available separately and are available for Unix as well. A little tutorial is available here.
This wiki page is a good start. In summary, all the major GUI libraries now have Lua bindings. Probably the most full-featured and well-maintained binding is wxLua There is a binding to Tcl/Tk. and also to Qt. An easy and lightweight alternative for more casual scripting is IUP; both IUP and wxLua are part of Lua for Windows but they are available separately and are available for Unix as well.