## Identifying your system ##
We'll assume you're using either Mac OS X, or Windows, or Linux.
If you're using **Mac OS X**, take note of what version of the Mac OS you're
running. (Under the Apple Menu, select "About this Mac".)
* Leopard (10.5)
* Snow Leopard (10.6)
* Lion (10.7)
* Mountain Lion (10.8)
* Mavericks (10.9)
* Yosemite (10.10)
If you're running **iOS**, you probably can't use this software on that machine. (A bit more below.)
Furthermore, you'll be in one of two subgroups:
* You'll have Apple's Xcode and the independent MacPorts system
installed. (Probably you don't. If you don't know what I'm talking about, you don't have these.)
If you don't have these, but want to try this route, you can read about
the MacPorts system at .
This automates the building of Unix-type software on your Mac; it
makes it a lot easier to check for dependencies, use more-recent
versions of things, and so on. (Though as it happens, MacPorts only has an older version of
our chosen implementation of Scheme.)
Xcode is available at
. Some
versions of this have been available for free, though you do have to
register with Apple as an "Apple Developer", which involves accepting a
legal agreement with Apple. I have an older version of this installed.
If you download a recent version, email me and let me know how the
process works so I can tell others. There are instructions about how to
get Xcode in the MacPorts installation guide.
* Or you won't have those installed. (**Most Mac users will be in this group.**)
Then you'll need pre-packaged (and usually pretty GUI) installers for
everything. These are great when they're available and kept up-to-date;
however sometimes those conditions aren't met.
If you're using **Windows**, you'll be in one of two subgroups:
* You'll have the Cygwin system
installed.
This puts a Unix-like layer on top of your Windows system,
and makes it easier for you to use the same software everybody
else will be using, without its needing as much special-for-Windows
treatment. However, many of you won't have this installed.
* You won't have Cygwin installed. You might in theory have
a different group of compilers installed (Microsoft Visual C++) but
we'll assume that the overwhelming majority of users in this group
don't have access to a compiler and need pre-packaged installers
for everything.
If you're using **Linux**, you could be using any one of numerous packaging
systems.
* We'll give examples using the packaging system shared by Debian and Ubuntu,
and we'll assume that those of you using different packaging systems will know
how to make the relevant substitutions. You may also want to take note of the
output of the "uname -srm" command. On my machine this tells me "Linux
3.12.8-extrastuff x86\_64". That tells me I'm running the x86\_64 (as opposed to the
i686 or i386 or whatever) version of Linux, and that I'm running kernel
version 3.12.8.
**For all of these groups**, a general item to take note of is what "processor architecture" your machine is running. Three of the possibilities are:
* One of Intel's i386, i486, i586, i686 architectures. These are collectively known as "x86" or "IA-32" or sometimes just "32-bit".
* Intel or AMD's x86\_64 architecture. This is sometimes also called "x64" or "amd64" or "IA-64" or sometimes just "64-bit".
* ARM or some other architecture. These are generally lower-powered machines, like iPads. Some of the software we're proposing *might* in principle be capable of running on such machines, but installers don't seem to be available. We'll assume you have access to an x86 or x86\_64 machine.
In the Linux example above, I could tell my machine is running x86 because the
result of the `uname` command said "i386" at the end. Another machine I have
says "x86\_64" at the end. On a Mac, you can also say `uname -m` in a Terminal
session, and it will say something like "i386". I think that Mac OS's from Lion
/ 10.7 forward have all been x86\_64-only. On Windows, I don't know how to
collect this information. But generally, machines running Windows XP will
probably be i386/32-bit (unless it's a version of Windows with "64-bit" or
"x64" in its title); machines running Windows Vista or Windows 7 or Windows 8
could be running either x86/32-bit or x64/64-bit.
(Update: I found
[this Microsoft page](http://windows.microsoft.com/en-us/windows/32-bit-and-64-bit-windows)
that may help.)
## PLEASE REPORT PROBLEMS (AND SOLUTIONS!) ##
We haven't tested these instructions ourselves, and they're not explicit
step-by-step instructions in any case. If you encounter troubles, please email
to let us know so that we can amend the instructions to help others. If you
figure out how to fix the problem youself (and please do), please also write
with suggestions how we can change these instructions to make the process
easier and more straightforward for others.
## Getting Scheme ##
**Scheme** is one of two major dialects of *Lisp*, which is a large family of
programming languages. The other dialect is called "Common Lisp." Scheme is the
more clean and minimalistic dialect, and is what's mostly used in academic
circles.
Scheme itself has umpteen different "implementations", which share most of
their fundamentals, but have slightly different extensions and interact with
the operating system differently. One major implementation used to be called
PLT Scheme, but then a few years ago changed their name to Racket.
This is what we recommend you use. (If you're already using or comfortable with
another Scheme implementation, though, there's no compelling reason to switch.)
Racket stands to Scheme in something like the relation Firefox stands to HTML. It's one program among others for working with the language; and many of those programs (or web browsers) permit different extensions, have small variations, and so on.
Racket has several components. The two most visible components for us are a command-line interpreter named "racket" and a teaching-friendly editor/front-end named "DrRacket". You will probably be working primarily or wholly in the latter.
* In your web browser:
There is a (slow, bare-bones) version of Scheme available for online use at .
* **To install in Windows**
Go to . Download and install the "Windows x64" version. (Or the "Windows x86" verson if you have an older, 32-bit system.)
* **To install on Mac without MacPorts**
Go to . Download and install the option for your system, most likely "Macintosh
OS X (Intel 64-bit)".
* **To install on Mac with MacPorts**
You can install a command-line version of
PLT Scheme (dating from early 2009) by opening a Terminal
and typing:
sudo port install mzscheme
If you want the GUI components, I think you'll need to use the
"Mac/without MacPorts" installation options above.
I recommend also typing:
sudo port install rlwrap
then if you ever use the command-line program `mzscheme` (or `racket`), you should start it by typing `rlwrap mzscheme`. This gives
you a nice history of the commands you've already typed, which you can scroll up and down in with your
keyboard arrows.
* **To install on Linux**
Use your packaging system, for example, open a Terminal and
type:
sudo apt-get install racket
It's very likely that your packaging system has some version of
Racket available, so look for it. However, if you can't find it you
can also install a pre-packaged binary from the Racket website at .
Choose the option for your version of Linux (Ubuntu and Debian are available).
As above, I recommend you also type:
sudo apt-get rlwrap
then if you ever use the command-line program `mzscheme` (or `racket`), you should start it by typing `rlwrap mzscheme`. This gives
you a nice history of the commands you've already typed, which you can scroll up and down in with your
keyboard arrows.
## Getting OCaml ##
**Caml** is one of two major dialects of *ML*, which is another large family of
programming languages. The other dialect is called "SML" and has several
implementations. But Caml has only one active implementation, OCaml or
Objective Caml, developed by the INRIA academic group in France.
*Will add more information about this soon.*