-Identifying your system
-=======================
+## Notes ##
+
+* We were updating this page vigorously until about 2:30 pm on Saturday 31
+January. Now it is relatively stable, but we'll tweak it as we learn more. We
+encourage you to try to get the software set up sooner rather than later, and
+those who do so first should let us know how things go---whether it's smoothly
+or not---so that we might possibly refine or expand the instructions for
+others. It'd be great if you took careful notes of what you did, step by step.
+If our instructions are broken or misleading or incomplete, and you figure out
+how to fix them on your own, it'd also be great if you can tell us what went
+wrong and exactly what you did to achieve joy.
+
+* On a Mac or Linux system, you have a number of *system directories* such as `/usr` and `/Library`,
+ and also your *user home directory* which will be named something like `/User/george` or `/home/george`
+ if you are `george`. Other ways to refer to the user home directory are as `~` (the tilde character)
+ or as `$HOME`. When installing software, you sometimes have a choice of whether to install it into
+ the system directories or in subdirectories of your user home. When this choice was available,
+ I made the instructions that follow select the latter. This makes it somewhat harder for things
+ to get messed up, and makes it somewhat easier for you to remove things later.
+
+ If you're using a Mac without MacPorts (explained below), then Chicken and
+ OCaml will be installed under your user home; but Racket's and GHC's
+ Installers put them into system directories.
+
+
+## Identifying your system ##
We'll assume you're using either Mac OS X, or Windows, or Linux.
+If you're running **iOS**, you'll have a much harder time (perhaps impossible,
+perhaps not) getting this software to run on your machine, and we can't give
+you any guidance.
-If you're using Mac OS X, you'll be in one of two subgroups:
- * You'll have Apple's Xcode and the independent MacPorts system
- installed.
- Xcode is available at
- http://developer.apple.com/technologies/tools/xcode.html
- You have to register as an Apple Developer to download it. This
- is free but requires you to accept a legal agreement with Apple.
- The latest version of Xcode to work with Leopard is 3.14; more
- recent versions require Snow Leopard.
-
- The MacPorts system is available at
- http://www.macports.org/
- 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.
-
- * 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 those conditions aren't always met.
-
- IN EITHER CASE, take note of what version of the Mac OS you're running:
- "Tiger" 10.4, or "Leopard" 10.5, or "Snow Leopard" 10.6.
-
-
-If you're using Windows, you'll be in one of two subgroups:
- * You'll have the Cygwin system installed:
- http://www.cygwin.com/
- 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 ...), 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
+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)
+
+Furthermore, Mac users will 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 <http://www.macports.org/>.
+ 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.)
+
+ There are also other package management systems available for the Mac, notably Homebrew and Fink. I only know a little bit about them.
+
+ There are instructions about how to get Xcode on the [Installing MacPorts](https://www.macports.org/install.php) page.
+ Some versions of [Xcode](http://developer.apple.com/xcode.html) are available for free on the Mac App Store.
+ Other versions are available through Apple's Developer website (some of these are free, but do require you to
+ register with Apple as an "Apple Developer", which involves clicking to accept 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.
+ <!--
+ The latest version of Xcode to work with 10.5 / Leopard is 3.14; more recent versions (>= 3.2) require 10.6 / Snow Leopard.
+ 3.2.6 is last version that can be downloaded for free by users of 10.6 / Snow Leopard. (But if they pay, they can use up to Xcode 4.2.)
+ Xcode 4.1 was free to all users of 10.7 / Lion. Is Xcode 4.6.x still available for free? Are Xcode 5.x and/or 6.x available for free?
+ -->
+
+* 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 <http://www.cygwin.com/> 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. (**Most Windows users will be in this group.**)
+ You might in theory have a different group of compilers installed
+ (MinGW, or 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
- 2.6.35-ARCH 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 2.6.35.
-
-
-
-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 the two major dialects of Lisp. It's more clean and minimalistic than the other dialect, and is what's mostly used in academic circles.
-
-Scheme itself has umpteen different "implementations", which share a large common base, but differ slightly in what commands you use to print, inteact with the filesystem, tell the compiler to include one source file inside another, and so on. One major implementation used to be called PLT Scheme, and 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.)
-
-We say this "used to be called" PLT Scheme, because they just changed their name to "Racket." Not "Racket Scheme," just "Racket." Since the name change is so recent, you're likely to run across both sets of names.
-
-PLT Scheme had three salient components: the command-line version "mzscheme", a GUI extension "MrEd", and a teaching-friendly editor/front-end "DrScheme".
-In Racket these have been renamed "racket", "gracket", and "DrRacket", respectively.
-
- Windows: Go to:
- http://racket-lang.org/download/
- Download and install the "Windows x86" version.
-
- Mac/without MacPorts: Go to:
- http://racket-lang.org/download/
- Download and install the option for your system, most likely "Macintosh
- OS X (Intel)"
-
- 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.
-
- Linux users:
- Use your packaging system, for example, open a Terminal and
- type:
- sudo apt-get install plt-scheme
-
- It's very likely that your packaging system has some version of
- PLT Scheme available, so look for it. However, if you can't find it you
- can also install a pre-packaged binary from the Racket website:
- http://racket-lang.org/download/
- Choose the option for your version of Linux (Ubuntu, Debian, and two
- varieties of Fedora are available)
-
-
-Getting OCaml
-=============
-
-Caml is one of the two major dialects of ML. The other dialect is SML and has several implementations. Caml has only one active implementation, OCaml, developed by the INRIA academic group in France.
-
-It's helpful if in addition to OCaml you also install the Findlib add-on.
-This will make it easier to install additional add-ons further down the road.
-However, if you're not able to get that working, don't worry about it much.
-
-
- Windows:
- Go to:
- http://caml.inria.fr/download.en.html
- You can probably download and install the
- "Self installer for the port based on the MinGW toolchain"
- even if you don't know what MinGW or Cygwin are.
- Some features of this require Cygwin, but it looks like
- it should mostly work even for users without Cygwin.
- At the time of this writing, only an installer for the previous
- version of OCaml (3.11.0, from January 2010) is available.
-
- To install the Findlib add-on, you must have the
- Cygwin system installed. We assume few of you do,
- so we're not going to try to explain how to do this.
- If you want to figure it out yourself, go to the
- Findlib website:
- http://projects.camlcity.org/projects/findlib.html
-
- Mac/without MacPorts:
- To install OCaml 3.12 (just released the summer), go to:
- http://caml.inria.fr/download.en.html
- and download and install the "Binary distribution for Mac OS X"
-
- To install the Findlib add-on, you'll need the Xcode development tools
- to compile it yourself. Once you get that far, it's probably easiest
- for you to install MacPorts and just install things using the MacPorts
- instructions. (Use the MacPorts version of OCaml, instead of installing
- the package from the caml.inria.fr website, as described above)
- However, if you do have Xcode, and want to do without MacPorts, then
- what you need to do is download Findlib from:
- http://download.camlcity.org/download/findlib-1.2.6.tar.gz
- Unpack the download, open a Terminal and go into the folder you just
- unpacked, and type:
- ./configure
- make package-macosx
- This will build an installer package which you should be able to
- double-click and install.
-
- Mac/with MacPorts: you can install the previous version of OCaml (3.11.2,
- from January 2010), together with the Findlib add-on, by opening a Terminal
- and typing:
- sudo port install ocaml caml-findlib
-
- Linux: Use your packaging system, for example, open a Terminal and
- type:
- sudo apt-get install ocaml ocaml-findlib
- That will install a version of OCaml (probably 3.11.2, from January 2010)
- and the Findlib add-on.
-
- If for some reason you can't get OCaml through your
- packaging system, you can go to:
- http://caml.inria.fr/download.en.html
- Pre-packaged binary installers are available for several Linux systems.
-
- If you can't get findlib through your packaging system, you'll
- need to download it from:
- http://download.camlcity.org/download/findlib-1.2.6.tar.gz
- and use gcc to compile it yourself. If you don't know how to
- do that, you probably don't want to attempt this.
- Here are the INSTALL notes:
- https://godirepo.camlcity.org/svn/lib-findlib/trunk/INSTALL
+
+* 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.
+
+
+**For everyone**, 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 also called "x64" or "amd64" or "IA-64" or sometimes just "64-bit". (Note that these *aren't* "x86" machines, even though "x86\_64" starts with those letters.)
+* 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.
+
+On Linux or Mac OS X, you can open a terminal and type `uname -m`. If the
+result is "x86\_64", then you've got x64/64-bit. If it's "i386" or something
+like that, then you've got x86/32-bit. I think that Mac OS Xs from 10.7 / Lion
+forward have all been x86\_64-only.
+
+On Windows,
+[here is a page that can help you figure this out](http://windows.microsoft.com/en-us/windows/32-bit-and-64-bit-windows).
+I think that most machines running Windows XP will be x86/32-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.
+
+
+## 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.
+
+
+## Preliminaries ##
+
+If you're using Linux or a Mac without MacPorts, then open a Terminal and type the following. You probably want to copy and paste it to make sure you don't make mistakes:
+
+ (IFS=:; for p in $PATH; do [ /usr/local/bin = "$p" ] && exit 0; done;
+ echo 'export PATH="/usr/local/bin:$PATH"' >> ~/.bash_profile)
+ mkdir -p ~/bin
+ echo 'export PATH="$HOME/bin:$PATH"' >> ~/.bash_profile
+
+
+## Getting Scheme ##
+
+**Scheme** is one of two or three major dialects of *Lisp*, which is a large family
+of programming languages. The other dialects are called "Common Lisp" and "Clojure".
+Scheme is the more clean and minimalist dialect, and is what's mostly used in
+academic circles.
+
+* In your web browser:
+
+ There is a (slow, bare-bones) version of Scheme available for online use at <http://tryscheme.sourceforge.net/>.
+
+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 is called [Racket](http://racket-lang.org),
+and that is what we recommend you use. (A few years back they were called PLT Scheme, but then
+they changed their name to Racket.)
+If you're already using or comfortable with
+another Scheme implementation, though, there's no compelling reason to switch.
+
+
+Another good Scheme implementation is [Chicken](http://www.call-cc.org). For our purposes, this is in some respects
+superior to Racket, and in other respects inferior. If you have any issues with installing or using Racket, you could
+try this out instead. You might even want to install both.
+
+<!--
+Racket doesn't have R7RS-small, and won't anytime soon.
+Other R7RS-friendly: [Gauche](http://practical-scheme.net/gauche), [Chibi](https://code.google.com/p/chibi-scheme).
+-->
+
+Racket and Chicken stand to Scheme in something like the relation Firefox stands to HTML. They are two programs (or platforms) among others for working with the Scheme 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.
+<!-- "racket" used to be mzscheme, "DrRacket" used to be DrScheme -->
+
+The current version of Racket is 6.1.1 (released November 2014).
+
+* **To install in Windows**
+
+ Go to <http://racket-lang.org/download/>. 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 <http://racket-lang.org/download/>. Download and install the option for your system, most likely "Macintosh
+ OS X (Intel 64-bit)".
+
+ After you copy the files from the Installation disk to your /Applications folder, I think it's helpful to do these additional steps. In a Terminal, type:
+
+ sudo ln -s /Applications/Racket*/DrRacket.app /Applications/
+ ln -s /Applications/Racket*/bin/racket ~/bin/
+
+ (If you get an error about ".../bin/: No such file or directory", then you didn't follow the Preliminary instructions above.)
+
+ Then you can launch Racket either by double-clicking the DrRacket icon in
+ your Applications folder (this gives you the GUI interface); or by typing
+ `racket` in a Terminal (this gives you the command-line version).
+
+ Instead of, or in addition to, the first line above, you could drag the *DrRacket.app* icon to your Dock.
+
+* **To instead install Chicken Scheme on Mac without MacPorts**
+
+ Here are the exact steps I just verified worked. Note that I *first installed the Haskell Platform*, described further down this page; that installed some developer tools that were needed to build and install Chicken. If you don't know how to open a Terminal, move between directories, copy / rename / delete files and so on, then you're probably best off not doing this. You could break something.
+
+ 1. Go to <http://code.call-cc.org>, and click the "Source code" link near the top. Current version is 4.9.0.1, released November 2014. This should fetch a file to your download folder, and will probably automatically unpack that file into a folder, "chicken-4.9.0.1". Click on that folder and press command-C / Copy, then open a Terminal.
+ 2. In the terminal type `cd` followed by a space, then press command-V / Paste. Then press enter. This will move your session into the folder you just downloaded. <!-- Type `less README` and read that file. -->
+ 3. Type `make PLATFORM=macosx XCODE_DEVELOPER= XCODE_TOOL_PATH=/usr/bin PREFIX=$HOME` <!-- PREFIX defaults to /usr/local -->
+
+ The options starting with `XCODE_` are to tell the Chicken build scripts that I've got the developer tools installed in my main system, rather than as part of Xcode. (That's where the Haskell Platform installer put them.) Continuing:
+
+ 4. Wait a while while Chicken builds.
+ 5. If it finishes with no errors, then type `make PLATFORM=macosx XCODE_TOOL_PATH=/usr/bin PREFIX=$HOME install`. This will install Chicken in your user home directory.
+ 6. At this point you can type `which chicken`. It should give you an answer of "/Users/yourname/bin/chicken".
+ 7. In your terminal, type `chicken-install r7rs datatype matchable monad`. <!-- with "-sudo" if you installed chicken in /usr/local --> This will download, build, and install a few extensions (Chicken calls them "eggs") relevant to ideas we'll be working with in this course.
+
+* **To install on Mac with MacPorts**
+
+ Unfortunately, MacPorts doesn't have Racket itself available. It only has an older version from when they still called
+ themselves PLT Scheme. And even then, it only has the command-line program "mzscheme" (what's nowadays called "racket"); it
+ doesn't have the GUI program that corresponds to what's now called "DrRacket". You can install mzscheme by opening a Terminal
+ window and typing:
+
+ sudo port install mzscheme
+
+ <!-- mzscheme v4.1.5, from March 2009; latest mzscheme is 4.2.5, from April 2010 -->
+
+ If you want the GUI components, I think you'll need to use the
+ "Mac/without MacPorts" installation options above. Or you could try the Chicken Scheme implementation instead of Racket. This is more current.
+ To do that, type:
+
+ sudo port install chicken readline
+
+ <!-- chicken v4.8.0.2, from Feb 2013; latest available is 4.9.0.1, from Nov 2014 -->
+
+ Whether you use mzscheme or Chicken, I recommend also typing:
+
+ sudo port install rlwrap
+
+ then if you ever use the command-line program `mzscheme` (or `racket`, for that matter), you should start it by typing `rlwrap mzscheme` (or whatever). 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 <http://racket-lang.org/download/>.
+ 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` (or whatever). 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.
+Sometimes we may refer to Caml or ML
+more generally; but you can assume that what we're talking about always works more
+specifically in OCaml.
+
+It's helpful if in addition to OCaml you also install the
+Findlib add-on and/or the [OPAM](https://opam.ocaml.org) "package manager."
+These will make it easier to install additional add-ons further down the road.
+However, if you're not able to get them working, don't worry about it much.
+
+The current version of OCaml is 4.02.1 (released October 2014).
+<!-- 3.12.1 July 2011; 4.00.1 Oct 2012; 4.01.0 Sept 2013; 4.02.0 Aug 2014; 4.02.1 Oct 2014 -->
+
+
+* In your web browser:
+
+ There is a (slow, bare-bones) version of OCaml available for online use at <http://try.ocamlpro.com/>.
+
+
+* **To install in Windows**
+
+ There are *five* different strategies for installing OCaml on Windows. I don't know which works best.
+
+ 1. First, you can go to <http://caml.inria.fr/download.en.html>.
+ You can probably download and install the
+ "Self installer for the port based on the MinGW toolchain"
+ even if you don't know what MinGW or Cygwin are.
+ Some features of this require Cygwin, but it looks like
+ it should mostly work even for users without Cygwin.
+ At the time of this writing, only an installer for an earlier
+ version of OCaml (4.01.0, from September 2013) is available.
+
+ 2. A second strategy uses a package called
+ [OCPWIN](http://ocaml.org/docs/install.html#OCPWINSelfContainedOCamlforWindows). This also installs only version 4.01.0.
+
+ 3. The [three remaining strategies](http://ocaml.org/docs/install.html#OCamlonCygwin) in some way
+ use the Cygwin environment, mentioned earlier on this page. At least one of
+ those three methods will automatically fetch and help you install Cygwin.
+ The first method listed on that page says it installs version 4.00.1, but
+ really it's been updated and now installs the (somewhat newer, but still
+ not the newest) version 4.01.0.
+
+ Some of these methods may automatically install Findlib for you. If not,
+ you can try installing it yourself but I think you'll need the Cygwin
+ system installed to do so. I'm not going to explain how to do this.
+ If you want to figure it out yourself, go to the
+ Findlib website at <http://projects.camlcity.org/projects/findlib.html>.
+
+* **To install on Mac without MacPorts**
+
+ The people in charge of OCaml (they're at the French research institute INRIA) have stopped making pre-built packages for Mac OS X. One option you have is to use their package for a slightly older version of OCaml, 4.01.1 from Sept. 2013. You can find that as a "Precompiled binary for Mac OS X" on [this page](http://ocaml.org/releases/4.01.0.html). If, when you attempt to install this package, you get an error about its being from an "unidentified developer," you need to control-click on the `ocaml.pkg` file and select "Open", then when the warning box appears again, this time there will be an "Open" button that you can click. Then you can continue running the Installer.
+
+ A second option is to install the OPAM package manager and use that to build and install the latest version of OCaml. Here's how to do that:
+
+ 1. Download [this file](https://raw.github.com/ocaml/opam/master/shell/opam_installer.sh) and
+ note where it gets saved to. If it opens in your browser, then type
+ command-S / Save Page and save it somewhere on your disk, again noting its
+ location.
+
+ 2. Open a terminal and type:
+
+ sh /path/to/opam_installer.sh ~/bin
+
+ Except replace `/path/to` with the real location, that you noted in step 1. When prompted "Do you want OPAM to modify ~/.bash_profile and ~/.ocamlinit?", say "y".
+
+ 3. If that works, then type:
+
+ opam init --comp 4.01.0
+
+ or whatever it was that the OPAM installer prompted you to type. This will download and install a fresh version of OCaml, and will take a bit of time.
+
+<!-- To upgrade: opam switch 4.02.1 && eval `opam config env` -->
+
+<!--
+If you do have Xcode, and want to do without MacPorts, then
+what you need to do is download Findlib from
+<http://download.camlcity.org/download/findlib-1.2.6.tar.gz>.
+Unpack the download, open a Terminal and go into the folder you just
+unpacked, and type:
+
+ ./configure
+ make package-macosx
+
+This will build an installer package which you should be able to
+double-click and install.
+-->
+
+* **To install on Mac with MacPorts**
+
+ You can install the current version of OCaml (4.02.1, from October 2014),
+ together with the Findlib add-on and OPAM package manager, by opening a Terminal and typing:
+
+ sudo port install ocaml ocaml-findlib opam
+
+ As with Scheme, it's helpful to also have rlwrap installed, and to start OCaml as `rlwrap ocaml`. 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 ocaml opam camlp4-extra ocaml-findlib
+
+ That will install a version of OCaml and the Findlib add-on and OPAM package manager.
+
+ If you're using Ubuntu "Utopic" (14.10), there's [a note on the OPAM home page](https://opam.ocaml.org/doc/Install.html)
+ warning that its version of OPAM is broken, and not to use it. Here's how you can get (OCaml and) OPAM from a newer repository:
+
+ sudo apt-get install -y software-properties-common
+ sudo add-apt-repository -y ppa:avsm/ppa
+ sudo apt-get update
+ sudo apt-get install ocaml opam
+
+ If for some reason you can't get OCaml through your Linux packaging system, you can go to
+ <http://caml.inria.fr/download.en.html>.
+ Pre-packaged binary installers are available for several Linux systems.
+
+ If you can't get findlib through your packaging system, you'll need to download it from
+ <http://download.camlcity.org/download/findlib-1.5.5.tar.gz>.
+ and use gcc to compile it yourself. If you don't know how to do that, you probably don't want to attempt this.
+ Here are the INSTALL notes:
+ <https://godirepo.camlcity.org/svn/lib-findlib/trunk/INSTALL>.
+
+ As with Scheme, it's helpful to also have rlwrap installed, and to start OCaml as `rlwrap ocaml`. 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 Haskell ##
+
+This last installation is less crucial than the others, since we will be focusing
+primarily on Scheme and OCaml. However we, and the readings you come across,
+will sometimes mention Haskell, so it might be worth your installing this too,
+so that you have it available to play around with.
+
+Haskell is used a lot in the academic contexts we'll be working through. At one point, Scheme
+dominated these discussions but now Haskell seems to do that.
+
+Haskell's surface syntax differs from Caml, and there are various important things one can do in
+each of Haskell and Caml that one can't (or can't as easily) do in the
+other. But these languages also have *a lot* in common, and if you're
+familiar with one of them, it's generally not hard to move between it and the
+other.
+
+* In your web browser:
+
+ There is a (slow, bare-bones) version of Haskell available for online use at <http://tryhaskell.org/>.
+
+Like Scheme, Haskell has a couple of different implementations. The dominant one, and the one we recommend you install, is called [GHC](https://wiki.haskell.org/GHC), short for "Glasgow Haskell Compiler". To install this on your machine, there are a couple of different strategies. It's helpful to understand some lingo as you begin this process:
+
+* As mentioned, **GHC** is the main Haskell engine or compiler you'll be installing. The current version is 7.8.4, from December 2014.
+* **gcc** and **llvm/clang** and **Xcode** and **MinGW** are names for other compilers on various systems. Oftentimes these will be used during the installation process to get GHC up and running. Some of the strategies described below will help you install these if they're not already on your machine.
+* **alex** and **happy** and **haddock** are names of various Haskell helper programs that GHC uses to get up and running.
+* **[Cabal](https://www.haskell.org/cabal)** is a "package manager" for Haskell. It allows you to install libraries or extensions that other people have built. (Usually those are published at the [Hackage](https://hackage.haskell.org) web site.) Some of these are experimental and may not always work; others are quite fundamental and are almost de facto parts of what people expect in a Haskell system.
+* **[Haskell Platform](https://www.haskell.org/platform)** is a standard bundle that includes a specific version of GHC, plus specific versions of some of the most popular libraries or extensions. This is updated once or twice a year. The current version is 2014.2.0.0, from August 2014. It includes GHC version 7.8.3.
+
+The easiest way to get up and running with Haskell/GHC is to install the Haskell Platform. Here's how to do that **on Windows**:
+
+* Go to <https://www.haskell.org/platform/windows.html> and follow the instructions. It looks like this process will automatically install the MinGW compiler needed to get this build of Haskell running on Windows.
+
+On **Mac without MacPorts**:
+
+* Go to <https://www.haskell.org/platform/mac.html> and follow the instructions. This requires Mac OS X 10.6 / Snow Leopard or later; but there is a link to an earlier version of Haskell Platform, that's built for Mac OS X 10.5 / Leopard. During the installation, you may be prompted to install "the command line developer tools"; this is a portion of what Apple bundles together with Xcode (mentioned above on this page). The installer will take care of getting these for you if you give it permission.
+
+<!--
+The Installer places everything in your system directories. If you'd like it instead in your user directory (easier to clean up later), you can do this after running the Installer:
+
+ mkdir ~/Library/Frameworks
+ cp -a /Library/Frameworks/GHC.framework ~/Library/Frameworks/
+ [ -d ~/Library/Haskell ] && mv ~/Library/Haskell ~/Library/Haskell.orig
+ sudo mv /Library/Haskell ~/Library/
+ sudo chown -Rh $USER:staff ~/Library/Haskell
+ mkdir -p ~/share/doc ~/share/man/man1
+ ln -s ~/Library/Frameworks/GHC.framework/Versions/Current/usr/share/doc/ghc ~/share/doc/
+ ln -s ~/Library/Frameworks/GHC.framework/Versions/Current/usr/share/man/man1/ghc.1 ~/share/man/man1/
+ sudo rm -r /usr/share/doc/ghc /usr/share/man/man1/ghc.1 /Library/Frameworks/GHC.framework
+ for f in ghc ghc-7.8.3 ghc-pkg ghc-pkg-7.8.3 ghci ghci-7.8.3 haddock haddock-ghc-7.8.3 hp2ps hpc hsc2hs runghc runghc-7.8.3 runhaskell; do
+ ln -s ~/Library/Frameworks/GHC.framework/Versions/7.8.3-*/usr/bin/$f ~/bin/
+ sudo rm /usr/bin/$f
+ done
+ for f in activate-hs alex cabal cabal.real cabal.wrap ghc-clang-wrapper happy HsColour uninstall-hs; do
+ ln -s /Library/Haskell/ghc-7.8.3-*/bin/$f ~/bin/
+ sudo rm /usr/bin/$f
+ done
+ sed -i "" "s=/Library=$HOME/Library=g" $(fgrep -RIl /Library ~/Library/Haskell ~/Library/Frameworks/GHC.framework | fgrep -v .html)
+
+# Ehh. Doesn't work...
+-->
+
+On **Mac with MacPorts**:
+
+* In a Terminal, type `sudo port install haskell-platform`.
+
+On **Ubuntu or Debian Linux**:
+
+* In a Terminal, type `sudo apt-get install haskell-platform`.
+
+
+It's useful to know about the general [Haskell wiki](https://wiki.haskell.org) (not restricted to just GHC). They have a [Getting Started](https://wiki.haskell.org/Haskell_in_5_steps) page, which also recommends that you install the Haskell Platform.
+
+If any of the instructions above don't work, then you can try alternative instructions for [Mac](http://new-www.haskell.org/downloads/osx) or [Windows](http://new-www.haskell.org/downloads/windows) or [Ubuntu](http://new-www.haskell.org/downloads/linux). Note that this method doesn't install all the extensions that are part of the Haskell Platform, but only the core pieces of GHC. You can use Cabal to download and manage any extra extensions you turn out to need, down the road.
+
+**After installing Haskell**, open a Terminal and type:
+
+ cabal update
+
+It may give you a message about updating your `PATH` variable. On my Mac, I was prompted to do this:
+
+ echo 'export PATH="$HOME/Library/Haskell/bin:$PATH"' >> ~/.bash_profile
+
+On a Linux machine, or if you installed Haskell differently on your Mac, you might have to type instead:
+
+ echo 'export PATH="$HOME/.cabal/bin:$PATH"' >> ~/.bash_profile
+
+Some instructions may say to use `.bashrc` instead of `.bash_profile`. These files do similar jobs.
+
+After issuing the relevant `echo` command, I exited the Terminal and started a new Terminal session. Now if I type `echo $PATH` I should see the directory I just added in the list. Now I can contine setting up Cabal. I type:
+
+ which alex happy
+
+If that gives me back two pathnames, one to the program `alex` and the other to the program `happy`, then I'm already finished. If not, then I type:
+
+ cabal install alex happy
+
+This installs those two programs. They are helpers that Cabal needs to build and install some packages.
+
+<!-- https://github.com/pittsburgh-haskell/haskell-installation -->