Tools

CGILua
Uses Lua as server-side scripting language to make dynamic Webpages. Supports pure Lua scripts and HTML templates, which can be handled via CGI, FastCGI, mod_lua, ISAPI, and other APIs.
http://www.keplerproject.org/cgilua/

CPB
Lua to C/C++ binding library. Open source, free.
http://www.thomasandamy.com/projects/CPB/

Decoda
A Lua IDE and graphical debugger with source code control (SCC) support, syntax highlighting.
http://www.unknownworlds.com/decoda

Doris
Lua binding to OpenGL graphics API and GLUI OpenGL widget set. Open source, GPL.
http://doris.sourceforge.net/

Kepler Project
Lua Web development platform, has CGILua, LuaSQL, and other libraries, open source and binary distributions.
http://www.keplerproject.org/

Ldb
Lua debugger. Free for academic, non profit use.
http://www.inf.puc-rio.br/~roberto/ldb.html

Lua Cheia
Lua distribution with many useful libraries, that can be loaded dynamically, or built into the interpreter. Makes Lua more usable as stand-alone language.
http://luacheia.lua-users.org/

Lua Player
Script player for Sony PSP; makes writing games for PSP somewhat easier.
http://www.luaplayer.org/

Luabind
Library to make bindings between C++ and Lua; description, manual, links. Rasterbar Software. Open source, MIT license.
http://www.rasterbar.com/products/luabind.html

LuaEdit
Lua 5.0 IDE, debugger, script editor: syntax highlighting, completion proposal list, parameter proposition engine, advance breakpoint management, watches, project oriented management, lists functions, variables (global, local).
http://luaedit.luaforge.net

LuaJava
Scripting tool for Java; lows scripts coded in Lua manage components coded in Java, with no need for declarations or any kind of preprocessing.
http://www.keplerproject.org/luajava/

LuaJIT
Just-in-time (JIT) compiler for Lua. [Open source, MIT/X license]
http://luajit.org/

Lua.NET
Project integrates Lua with Common Language Infrastructure, a framework for language interoperability.
http://www.lua.inf.puc-rio.br/luanet/

LuaSocket
Lua extension library; gives support for TCP and UDP transport layers within Lua.
http://www.tecgraf.puc-rio.br/~diego/professional/luasocket/

Plua
Port of Lua 4.0, plus a small IDE, for PalmOS handheld devices.
http://netpage.em.com.br/mmand/plua.htm

PowerBLua
PowerBASIC wrapper for calling Lua functions.
http://mark0.ngi.it/code-powerblua-e.html

TkLua
Tk to Lua binding. Freeware.
http://www.tecgraf.puc-rio.br/~celes/tklua/

toLua
Simplifies integrating C/C++ code with Lua, automatically generates binding code to access C/C++ features from Lua; maps C/C++ constants, external variables, functions, classes, and methods to Lua, via Lua API and tag method facilities. Freeware.
http://www.tecgraf.puc-rio.br/~celes/tolua/