ZeroBrane Studio supports debugging of LuaJIT applications in several ways:

  1. (v0.39+) LuaJIT (v2.0.2) interpreter is included in ZeroBrane Studio and is the default interpreter (Project | Lua Interpreter | Lua).
  2. A LuaJIT application can be debugged as any other application using remote debugging.

Or, if you are running v0.38 or earlier:

  1. A LuaJIT interpreter can replace the default Lua interpreter used by ZeroBrane Studio. To do that, you need to set path.lua = "/full/path/to/luajit_executable" in cfg/user.lua. This setup will use luasocket bundled with ZeroBrane Studio. If your LuaJIT version is not compatible with luasocket (for example, you compiled LuaJIT for 64bit, but included luasocket is 32bit), you will need to compile luasocket yourself and make the libraries available to your script.
  2. If running on Windows, another option (assuming LuaJIT is compiled for 32bit) is to simply replace bin/lua51.dll with lua51.dll from LuaJIT. This will make ZeroBrane Studio itself to run on LuaJIT as well as all Lua processes started from it (in this case path.lua changes are not needed). With this option both the local console will provide access to the LuaJIT interpreter.

Make sure you use the latest version of LuaJIT (at least v2.0.1+) as it is needed to enable all debugging features. Also note that LuaJIT debugging behavior is slightly different from Lua 5.1: it may step on the same line several times (which is not a bug); Lua 5.1 will only step several times if it leaves the line (for example for a function call), and then returns back to it.

what a breath of fresh air. (doctorbling)

IMHO, ZBS is the fastest, most-flexible, best-thought-out IDE AND Debugger I've used since I began coding professionally in 1980. (Michael Berlyn)

Love ZeroBrane Studio. Lightweight. Works. Powerful. (Ross Berteig)

Love the debugger, saving my life. (Troy Sandal)

Thanks again for your awesome IDE. I've moved over to it, forsaking my previous investment in Decoda! (Stephen Nichols)

my kids love ZeroBrane. (Phil Hagelberg)

ZBS is beautiful experience. I am using it usually 10 hrs every day w/o problems. (Srdjan Markovic)

...heartily recommend it. (stun)

I love ZBS. I use it for all of the work I’ve started doing in Lua...! This IDE is fantastic! (Eddie Dover)

ZeroBrane Studio has got a working debugger, full IDE feature set, small footprint, and is completely customizable in lua. You have no idea how excited I was to find this little gem! (Jonathan Shieh)

It's a joy to use;... totally rock solid. (Jeff Smith)

Complaining about Zerobrane is like complaining that a beautiful spring day is a couple degrees too warm. (Jim Burnes)