The answer, as with many things is: it depends. What does your CLI app do? What platforms are you intending it run on? Is it going to be doing a lot of CPU-int

The answer, as with many things is: it depends. What does your CLI app do? What platforms are you intending it run on? Is it going to be doing a lot of CPU-intensive work? Is this CLI app going to be long-lived, run infrequently (e.g. fsck), or run perhaps many times a day by an actual real user (e.g. grep)? Is your app expended to be part of a Unix pipeline? All of these things are the real deciding factor between a compiled language and scripting language. If it's not doing anything particularly computationally expensive, perhaps a scripting language like Ruby or Python. Hell, you could even do it with JavaScript with NodeJS. CLI apps are usually utilities and their start-up time often matters. With any of these scripting languages there will be a palpable start-up time. This might not be so important if your CLI app is to be run infrequently, or is otherwise something that's long-running. If you're writing something that's going to munch and crunch data, or is otherwise doing a lot of calculations, or is going to be run frequently and needs a fast start up time, Go, C, C++ are good bets. There are probably others that may be appropriate, but I'm not familiar with Haskell, etc. The vast majority of CLI utilities are written in C or C++ and this is for a reason. Not many are written in scripting languages, although some are, such as Puppet, Vagrant, Fabric, etc.