Getting started / Tutorials

Advanced Installation

Roswell as a scripting environment

Roswell as an implementation manager

Roswell as a Testing Environment

Distributing applications


For Developers/Maintainers


Roswell - Common Lisp environment setup Utility.

Roswell is a Lisp implementation installer/manager, launcher, and much more! It started as a command-line tool with the aim to make installing and managing Common Lisp implementations really simple and easy.

Roswell has now evolved into a full-stack environment for Common Lisp development, and has many features that makes it easy to test, share, and distribute your Lisp applications. We aim to push the Common Lisp community to a whole new level of productivity.

Roswell is still in beta. Despite this, the basic interfaces are stable and not likely to change. It currently works well on Unix-like platforms such as Linux, Mac OS X and FreeBSD. It is also expected to work on other operating systems, but currently some parts or features might be missing or unstable.

Checkout the issues list if you are interested in what's lacking.

For those who are hesitant, here is the Policy on how Roswell affects or manipulates your system.

Installation, Tutorials

See Installation guide for details. We provide prebuilt binaries for various package managers. Instances include homebrew (OSX), AUR (Arch linux), dpkg (Debian/Ubuntu) (experimental), and Windows. Building from the source is also available.

After the installation, we strongly recommend following Initial Recommended Setup.


  • Implementation Manager
  • Scripting environment (similar to cl-launch)
  • Building utility (similar to buildapp)
  • Novel : Easier setup for initializing a script
  • Novel : Better integration to the command-line interface (Bash completion, etc)
  • Novel : Infrastructure for bundling/installing the scripts to/from a quicklisp system
  • Novel : Better support for Windows environment (tested exhaustively)
  • Novel : Better integration to CI environment (e.g. Travis-CI, CircleCI, Coveralls)


Roswell has git-like subcommands which resemble that of cl-launch, buildapp.

$ ros
Common Lisp environment setup Utility.


   ros [options] Command [arguments...]
   ros [options] [[--] script-path arguments...]

   run       Run repl
   install   Install a given implementation or a system for roswell environment
   update    Update installed systems.
   build     Make executable from script.
   use       Change default implementation.
   init      Creates a new ros script, optionally based on a template.
   list      List Information
   delete    Delete installed implementations
   config    Get and set options
   version   Show the roswell version information

Use "ros help [command]" for more information about a command.

Additional help topics:


Use "ros help [topic]" for more information about the topic.

Managing/Installing Several Lisp Installations

$ ros install               # displays a list of all installable implementations

$ ros install sbcl-bin      # default sbcl
$ ros install sbcl          # The newest released version of sbcl
$ ros install ccl-bin       # default prebuilt binary of ccl
$ ros install sbcl/1.2.0    # A specific version of sbcl

$ ros list installed sbcl   # Listing the installed implementations
$ ros run -- --version      # check which implementation is used
SBCL 1.2.15
$ ros use sbcl/1.2.3        # change the default implementation

To use an implementation that was not installed by roswell, use i.e. ros use sbcl/system.

The list of supported implementations continues to grow!

Installing scripts

It is also possible to install scripts using ros install:

$ ros install qlot            # will install a program from quicklisp
$ ros install fukamachi/qlot  # will install it from the GitHub

To add installable scripts into the system, you need to put roswell scripts (files having .ros extensions) into a roswell subdirectory. Take a look at qlot's roswell/qlot.ros.

Scripting with Roswell

$ ros init
Usage: ros init [template] name [options...]

$ ros init fact
Successfully generated: fact.ros

$ emacs fact.ros
## editing the fact.ros ...

$ cat fact.ros
#|-*- mode:lisp -*-|#
exec ros -Q -- $0 "$@"

(defun fact (n)
  (if (zerop n)
      (* n (fact (1- n)))))

(defun main (n &rest argv)
  (declare (ignore argv))
  (format t "~&Factorial ~D = ~D~%" n (fact (parse-integer n))))

$ ./fact.ros 10
Factorial 10 = 3628800

Chef recipe for roswell

@Rudolph-Miller is providing a Chef recipe for setting roswell up.

Roswell with CircleCI

@fukamachi uses Roswell with CircleCI.

Name Origin

From ‘made with secret alien technology’.

I felt making it easier to use Lisp for people is a kind of making opportunity for humanbeings to mingle with alien technology. I recall ‘roswell incident’ by the concept. I'm not sure what you feel.


SANO Masatoshi (


  • Eitaro Fukamachi (
  • Tomoya KAWANISHI (
  • Masataro Asai (

Special Thanks to

  • Eitaro Fukamachi ( for naming this project.
  • Sunrin SHIMURA for keens/cim that motivate me to start this project.


Licensed under the MIT License.

Found a bug ?

Report it in the Issues page. If you find a bug, don't forget to include the following information in the report:

  • your OS and its version
  • ros version
  • ros config

Thanks !