- Juno - the official integrated development environment (IDE) for the Julia language
- Debugger.jl - the official Julia debugger
- Rebugger.jl - an expression-level debugger for Julia with a provocative command-line (REPL) user interface
- MagneticReadHead.jl - a Julia debugger based on Cassette.jl
- Infiltrator.jl - allows you to set a breakpoint in a local context, inspect local variables and the call stack, and execute arbitrary statements in the context of the current function's module
You might also enjoy:
- Traceur.jl - runs your code and tells you about any obvious performance traps
- Cthulhu.jl - descend into Julia code and see it in all its representations.